Hi Imran, So I am right with my answer. There is no IP header in Arp packet. ARP header itself has Ip Address.So ARP cannot be a unicast packet at Layer 3 and a broadcast at Layer 2.
Thanks guys for ur valuable suggestion FInally i confirmed from my tests that when a router native vlan doesnt match the switch native vlan and they r not in the same subnet, they cannot ping each other. Native vlan should be mandatory match for connection between switches inoder to maintain STP sanity and not go to blocked state. But when u talk about Routers and Switches running differnet native vlans. There is no DTP or STP in routers. So anyway the trunk will form and data traffic can or cannot pass through depends upon the IP connectivity. Because i have done 5 test cases where i have matched the native on routers and switches. and traffic , and I didnt match the native vlans on routers and switches and also the traffic goes fine. THen i put the vlan Ip address in differnet subnets and now it is not working. So it depends upon the connectivity between the Router and Switche Happy Labbing On Tue, Dec 13, 2011 at 8:27 AM, Pedram Zadeh <[email protected]>wrote: > I think it is not that simple! I am happy to call it layer 2.5 (as Scott > Morris dose on previous link). There is also a very valuable comment there > that Garry put in and I quote it here: > > He says: > > "I think we should classify a protocols running *directly* on particular > layer of OSI model (using the *transport services* of the protocols > running at lower layers and providing the *transport services* for the > protocols running at upper layer), and the protocols running *between > layers > * of the OSI model (using the *transport services* of the protocols > running at lower layers, not providing *transport services* to upper layer > protocols, but *specific supplementary services*). > > For example, > - ARP runs on top of a layer 2 (for instance, ARP using the transport > services of the layer 2 Ethernet and providing a *supplementary services > *for > layer 3 IP, *not transport services*)." > > and it pretty makes sense. > > For ARP it is not only having a specific type field number in layer 2 > (0x806) as you compare it with dot1q (in dot1q layer 2 header still > extended after tag); take a look at the link that Ali put in: > > http://www.networksorcery.com/enp/protocol/arp.htm > > It is defined on the way that can support layer 3-->2 address resolution > for any layer 3 protocols as well as on any layer 2 frame types. (not only > between ethernet in layer 2 and IP in layer 3) > > At the end, I am agree with you, who cares! > > Cheers, > Pedram. > > On Tue, Dec 13, 2011 at 1:34 PM, Matt Hill <[email protected]> wrote: > > > Far out... this is confusing. > > > > IP is IP - L3. > > Ethernet is L2. > > > > Lets go further. IP sits in an L2 frame - Ethertype 0x800 (??) ARP > > also sits in an L2 frame 0x806 (?? - CBFd googling). Trunking 802.1q > > is 0x8800 (????) > > > > It really is that simple. Furthermore, if I got one or even all of > > the ethertypes wrong I dont particularly care. > > > > Cheers, > > Matt > > > > CCIE #22386 > > CCSI #31207 > > > > On 13 December 2011 12:55, Pedram Zadeh <[email protected]> wrote: > > > ARP is an OSI layer 3 non-routable protocol. It is not layer 3 because > it > > > contains IP addresses on its header (as IP also is not the only OSI > > layer 3 > > > routed protocol); it is OSI layer 3 because it has its own specific > > header > > > coming after OSI layer 2 header. > > > > > > As you can see on the link you posted, it is defined on the way that > can > > > support layer 3-->2 address resolution for other protocols as well as > on > > > the other layer 2 frame types. > > > > > > This is long debate you can see on many threads around the net (like > > > following) but I think the key point is the concept of OSI layers that > > > makes it layer 3. > > > > > > https://learningnetwork.cisco.com/thread/36117 > > > > > > > > > On Tue, Dec 13, 2011 at 5:20 AM, Imran Ali <[email protected]> wrote: > > > > > >> CORRECTION : > > >> > > >> when i refer layer 3 header . i mean to say their is a field in ARP , > > that > > >> contains ip address of end host . > > >> > > >> so is ARP layer 2 or layer 3. debate :-) > > >> > > >> > > >> > > >> > > >> > > >> > > >> > > >> On Mon, Dec 12, 2011 at 8:59 PM, Imran Ali <[email protected]> > wrote: > > >> > > >> > kid, > > >> > > > >> > if the arp does not contain layer 3 header , then how does the end > > host > > >> > recognises it belongs to him ? > > >> > > > >> > also i would recommend you to learn Layer 2 broadcast address . it > is > > all > > >> > F's in destination field not all zero's .. > > >> > > > >> > how does arp works ? > > >> > > > >> > PC1 ----------- SW--------PC2 > > >> > > > >> > both belongs to one vlan > > >> > > > >> > .PC1 pings PC2 . > > >> > > > >> > Let say the ip add is 10.0.0.1 and 10.0.0.2 . > > >> > > > >> > arp packet l3= 10.0.0.2 > > >> > l2= FFF.-----FFF > > >> > > > >> > SW receives it and sends it to all ports except one port . > > >> > > > >> > it is head by BOB at 10.0.0.3 , TOM at 10.0.0.4 and PC2 ALSO . > > >> > > > >> > BECAUSE IT WAS BROADCAST > > >> > > > >> > NOW IF ARP DOES NOT CONTAIN LAYER 3 HEADER . HOW DOES THE INTENDED > > HOST > > >> > REPLIES ?? > > >> > > > >> > WHAT MAKES BOB AND TOM IGNORE THE PACKET ? > > >> > > > >> > > > >> > > > >> > > > >> > > > >> > since i am also a student , i would like you to immediately go to > ine > > >> > website , become a member to get Free access to CCNA arp COD . this > > >> > streaming ends in december last day . > > >> > > > >> > also look at apr fields here > > >> > > > >> > http://www.networksorcery.com/enp/protocol/arp.htm > > >> > > > >> > hth > > >> > > > >> > > > >> > > > >> > > > >> > On Mon, Dec 12, 2011 at 10:02 AM, CCIE KID <[email protected]> > > wrote: > > >> > > > >> >> Hi Imran, > > >> >> > > >> >> When router sends a frame , it sends a untagged frame which it > > believes > > >> >> that native vlan is 20 , and that frame reaches the switch and > switch > > >> see > > >> >> the frame as untagged as think that it belongs to native vlan 30 > and > > >> floods > > >> >> it to all ports which belong to this vlan 300 ( access port for > vlan > > 300 > > >> >> and trunk ports which carry all vlans ) . > > >> >> > > >> >> I didnt understood the point that ur talking about that ARP is a > > layer 2 > > >> >> broadcast i agree. How can u say that it is unicast for Layer 3 > > >> >> > > >> >> When a router generates a arp for ip 20.1.1.1 . tthe layer 2 header > > will > > >> >> be the source MAC of its own MAC and the dest MAC as broadcast only > > >> right > > >> >> ..... and inside the ARP header the Source IP is its won IP and > > Target > > >> IP > > >> >> is 20.1.1.1 . and source MAC will be its own MAC and Target MAC > will > > be > > >> >> 000000.. So There is no IP header in ARP packet.. > > >> >> > > >> >> So where does unicast comes into picture for LAyer 3 ? Even router > > has > > >> >> to create a broadcast packet for ARP. > > >> >> > > >> >> So now router sends a arp packet to create L2 header . It send a > > >> UNTAGGED > > >> >> frame as it belongs to a native vlan of 20 and it hits switch and > it > > >> >> updates the source MAC and sees it is a native vlan and it forwards > > to > > >> all > > >> >> trunk ports and also access ports for vlan 10. , So now another > > switch > > >> >> receives it and sends it to the destined host. > > >> >> > > >> >> SO Imran i guess , I am correct. Correct me if i am wrong > > >> >> > > >> >> Thank You > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> So when the switch receives the frame and see this a broadcast > > frame. it > > >> >> wil broadcast it to all ports except to that port which came in. > > >> >> > > >> >> > > >> >> On Sun, Dec 11, 2011 at 2:54 PM, Imran Ali <[email protected]> > > wrote: > > >> >> > > >> >>> *kid , your question was answered perfectly by Rob.* > > >> >>> > > >> >>> *first off what is the use of trunk . ?* > > >> >>> > > >> >>> *Ans: to carry traffic of more than one vlan* . > > >> >>> > > >> >>> *can i say if trunk is up , everthing is fine ?* > > >> >>> > > >> >>> *no many factors may prevent proper decapsulation and rechability > is > > >> >>> broken* > > >> >>> > > >> >>> *can you give me example when even though trunk is up . end hosts > > are > > >> >>> not talking ?* > > >> >>> > > >> >>> yes . "allowed vlan list " filtering traffiic and " native vlan > > >> >>> mismatch " > > >> >>> > > >> >>> *ok can you expalin me how native vlan mismatch prevent end host > > >> >>> talking to each other in same vlan ?* > > >> >>> > > >> >>> *look at config provied in above mail . * > > >> >>> ** > > >> >>> *router's native vlan is 20 . and switch native vlan is 30. so > when > > >> >>> router send packets to an ip in valn 20 . it sends them untagged , > > and > > >> i > > >> >>> repeat it with diff words " in its native " form like the one > > received > > >> >>> from PC . * > > >> >>> ** > > >> >>> *Swithch when it receives the packet believes it belongs to Vlan > > 30 , > > >> >>> because here in switch* vlan 30 is Native . > > >> >>> > > >> >>> *what made switch believe it belongs to vlan 30 ?* > > >> >>> > > >> >>> *because it is assumed that when ever i received a frame with out > > any > > >> >>> vlan tag it belongs to native vlan * > > >> >>> > > >> >>> *so it searches vlan 30 . This was a first packet . * > > >> >>> ** > > >> >>> *to build a packet router should know the mac address . so this > > paket > > >> >>> is ARP packet . * > > >> >>> ** > > >> >>> *how can you say that ?* > > >> >>> ** > > >> >>> *arp cache was empty as this is first time they are talking * > > >> >>> > > >> >>> *ok i agree it was arp packet sourced from router to switch , but > > what > > >> >>> happened to it ?* > > >> >>> > > >> >>> *for the switch its just a frame . and it made an assumption that > it > > >> >>> blongs to ITS NATIVE vlan that is vlan 30 .* > > >> >>> > > >> >>> *ok what happened next . ?* > > >> >>> > > >> >>> *arp is broadcast at layer 2 and unicast at layer 3 . so swithch > now > > >> >>> prepares for broadcasting the frame IN VLAN 30.* > > >> >>> > > >> >>> *that's fine but why it dint answered ?* > > >> >>> > > >> >>> > > >> >>> > > >> >>> *kid i leave this question to be ansered by you . if you have CCNA > > >> >>> concepts fresh in your mind , you will understand above explantion > > and > > >> >>> also be able to answer the question* . > > >> >>> > > >> >>> *OH that's why rechability is broken between the ip that belong > to > > >> >>> same vlan due to mismatch in Natve vlan ?* > > >> >>> > > >> >>> *absolutely !* > > >> >>> > > >> >>> *so NATIVE VLAN MISMATCH is bad ?* > > >> >>> > > >> >>> *exactly > > >> >>> * > > >> >>> On Sat, Dec 10, 2011 at 7:03 PM, CCIE KID <[email protected]> > > wrote: > > >> >>> > > >> >>>> Hi, > > >> >>>> > > >> >>>> Still my issue is not been resolved. > > >> >>>> So what can be the conclusion man > > >> >>>> > > >> >>>> Can any expert can pitch in an answer for that > > >> >>>> > > >> >>>> > > >> >>>> On Sat, Dec 10, 2011 at 8:28 PM, me you <[email protected]> > > wrote: > > >> >>>> > > >> >>>> > *CONCLUSION: We do NOT have full reachability despite the vlan > > >> >>>> mismatch.* > > >> >>>> > > >> >>>> > > > >> >>>> > I would agree with you that your set up work, but I disagree > > with a > > >> >>>> > general statement that Native Vlan mismatch does not matter > > between > > >> a > > >> >>>> > router and switch. 1 2811, 3 subinterfaces and 1 3750 > trunkport > > >> with > > >> >>>> 3 > > >> >>>> > vlans. Neither of the native vlans have reachability. > > >> >>>> > > > >> >>>> > > > >> >>>> > interface FastEthernet0/0 > > >> >>>> > > > >> >>>> > no ip address > > >> >>>> > > > >> >>>> > duplex auto > > >> >>>> > > > >> >>>> > speed auto > > >> >>>> > > > >> >>>> > ! > > >> >>>> > > > >> >>>> > interface FastEthernet0/0.10 > > >> >>>> > > > >> >>>> > encapsulation dot1Q 10 > > >> >>>> > > > >> >>>> > ip address 10.1.1.1 255.255.255.0 > > >> >>>> > > > >> >>>> > ! > > >> >>>> > > > >> >>>> > interface FastEthernet0/0.20 > > >> >>>> > > > >> >>>> > encapsulation dot1Q 20 native > > >> >>>> > > > >> >>>> > ip address 20.1.1.1 255.255.255.0 > > >> >>>> > > > >> >>>> > ! > > >> >>>> > > > >> >>>> > interface FastEthernet0/0.30 > > >> >>>> > > > >> >>>> > encapsulation dot1Q 30 > > >> >>>> > > > >> >>>> > ip address 30.1.1.1 255.255.255.0 > > >> >>>> > > > >> >>>> > > > >> >>>> > > > >> >>>> > 3750 > > >> >>>> > > > >> >>>> > interface GigabitEthernet1/0/1 > > >> >>>> > > > >> >>>> > switchport trunk encapsulation dot1q > > >> >>>> > > > >> >>>> > switchport trunk native vlan 30 > > >> >>>> > > > >> >>>> > switchport mode trunk > > >> >>>> > > > >> >>>> > end > > >> >>>> > > > >> >>>> > > > >> >>>> > interface Vlan1 > > >> >>>> > > > >> >>>> > no ip address > > >> >>>> > > > >> >>>> > ! > > >> >>>> > > > >> >>>> > interface Vlan10 > > >> >>>> > > > >> >>>> > ip address 10.1.1.2 255.255.255.0 > > >> >>>> > > > >> >>>> > ! > > >> >>>> > > > >> >>>> > interface Vlan20 > > >> >>>> > > > >> >>>> > ip address 20.1.1.2 255.255.255.0 > > >> >>>> > > > >> >>>> > ! > > >> >>>> > > > >> >>>> > interface Vlan30 > > >> >>>> > > > >> >>>> > ip address 30.1.1.2 255.255.255.0 > > >> >>>> > > > >> >>>> > > > >> >>>> > > > >> >>>> > 3750(config)#do ping 10.1.1.1 > > >> >>>> > > > >> >>>> > > > >> >>>> > Type escape sequence to abort. > > >> >>>> > > > >> >>>> > Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 > seconds: > > >> >>>> > > > >> >>>> > !!!!! > > >> >>>> > > > >> >>>> > Success rate is 100 percent (5/5), round-trip min/avg/max = > > 1/2/9 ms > > >> >>>> > > > >> >>>> > 3750(config)#do ping 20.1.1.1 > > >> >>>> > > > >> >>>> > > > >> >>>> > Type escape sequence to abort. > > >> >>>> > > > >> >>>> > Sending 5, 100-byte ICMP Echos to 20.1.1.1, timeout is 2 > seconds: > > >> >>>> > > > >> >>>> > ..... > > >> >>>> > > > >> >>>> > Success rate is 0 percent (0/5) > > >> >>>> > > > >> >>>> > 3750(config)#do ping 30.1.1.1 > > >> >>>> > > > >> >>>> > > > >> >>>> > Type escape sequence to abort. > > >> >>>> > > > >> >>>> > Sending 5, 100-byte ICMP Echos to 30.1.1.1, timeout is 2 > seconds: > > >> >>>> > > > >> >>>> > ..... > > >> >>>> > > > >> >>>> > Success rate is 0 percent (0/5) > > >> >>>> > > > >> >>>> > > > >> >>>> > Deb ip icmp on *Dec 10 14:36:59.527: ICMP: echo reply sent, src > > >> >>>> 10.1.1.1, > > >> >>>> > dst 10.1.1.2 > > >> >>>> > > > >> >>>> > *Dec 10 14:36:59.527: ICMP: echo reply sent, src 10.1.1.1, dst > > >> >>>> 10.1.1.2 > > >> >>>> > > > >> >>>> > *Dec 10 14:36:59.531: ICMP: echo reply sent, src 10.1.1.1, dst > > >> >>>> 10.1.1.2 > > >> >>>> > > > >> >>>> > *Dec 10 14:36:59.531: ICMP: echo reply sent, src 10.1.1.1, dst > > >> >>>> 10.1.1.2 > > >> >>>> > > > >> >>>> > *Dec 10 14:36:59.535: ICMP: echo reply sent, src 10.1.1.1, dst > > >> >>>> 10.1.1.2 > > >> >>>> > > > >> >>>> > --More-- > > >> >>>> > > > >> >>>> > *Dec 10 14:37:04.179: ICMP: echo reply sent, src 20.1.1.1, dst > > >> >>>> 30.1.1.2 > > >> >>>> > > > >> >>>> > --More-- > > >> >>>> > > > >> >>>> > *Dec 10 14:37:06.183: ICMP: echo reply sent, src 20.1.1.1, dst > > >> >>>> 30.1.1.2 > > >> >>>> > > > >> >>>> > --More-- > > >> >>>> > > > >> >>>> > *Dec 10 14:37:08.187: ICMP: echo reply sent, src 20.1.1.1, dst > > >> >>>> 30.1.1.2 > > >> >>>> > > > >> >>>> > --More-- > > >> >>>> > > > >> >>>> > *Dec 10 14:37:10.195: ICMP: echo reply sent, src 20.1.1.1, dst > > >> >>>> 30.1.1.2 > > >> >>>> > > > >> >>>> > --More-- > > >> >>>> > > > >> >>>> > *Dec 10 14:37:12.199: ICMP: echo reply sent, src 20.1.1.1, dst > > >> >>>> 30.1.1.2 > > >> >>>> > > > >> >>>> > > > >> >>>> > To say vlan mismatch between a router and a switch does not > > matter > > >> is > > >> >>>> > misleading or wrong. We could say if "this is that way" then > > "that > > >> is > > >> >>>> this > > >> >>>> > way" "that and this will work":) > > >> >>>> > > > >> >>>> > > > >> >>>> > Rob > > >> >>>> > > > >> >>>> > > > >> >>>> > > > >> >>>> > On Sat, Dec 10, 2011 at 5:39 PM, CCIE KID <[email protected] > > > > >> >>>> wrote: > > >> >>>> > > > >> >>>> >> Hi Oyebande, > > >> >>>> >> > > >> >>>> >> Thank u mate. U confirmed my understanding. So from router to > > >> switch > > >> >>>> it > > >> >>>> >> doesnt matter to match the native vlan on both sides. > > >> >>>> >> Unlike Switch to Switch to form trunk port ,native vlans > should > > >> >>>> match to > > >> >>>> >> form trunk link > > >> >>>> >> to pass data traffic on that link. > > >> >>>> >> > > >> >>>> >> Thanks all for their confirmation > > >> >>>> >> > > >> >>>> >> > > >> >>>> >> > > >> >>>> >> On Sat, Dec 10, 2011 at 5:19 PM, Oluwagbenga Oyebande < > > >> >>>> >> [email protected]> wrote: > > >> >>>> >> > > >> >>>> >>> > > >> >>>> >>> *CONCLUSION: We have full reachability despite the vlan > > >> mismatch.* > > >> >>>> >>> * > > >> >>>> >>> * > > >> >>>> > > >> >>>> >>> * > > >> >>>> >>> Three routers and one switch. > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> * > > >> >>>> >>> * > > >> >>>> >>> > > >> R2811(Fa0/0.1)-------------TRUNK-LINK-----------------------Cat3550 > > >> >>>> >>> (Fa0/1) > > >> >>>> >>> * > > >> >>>> >>> * > > >> >>>> >>> native vlan 20 > > >> >>>> >>> native vlan 10 > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> R3825 > > >> >>>> >>> (Gi0/0.1) > > >> >>>> >>> ------------- > > >> >>>> >>> TRUNK-LINK > > >> >>>> >>> ----------------------- > > >> >>>> >>> Cat3550 (Gi0/2) > > >> >>>> >>> native vlan 30 > > >> >>>> >>> > > >> >>>> >>> native vlan 10 > > >> >>>> >>> > > >> >>>> >>> *R2811-forvlan10(Fa0/0)--* > > >> >>>> >>> ACCESS-LINK > > >> >>>> >>> *-----* > > >> >>>> >>> Cat3550 (Fa0/4) > > >> >>>> >>> * > > >> >>>> >>> * > > >> >>>> >>> > > >> >>>> >>> explicitly configured in vlan 10 as access port > > >> >>>> >>> > > >> >>>> >>> I included the third link to clear all doubts about expected > > >> >>>> behaviour > > >> >>>> >>> of vlan 10 connected devices. > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> * > > >> >>>> >>> *Catalyst 3550 Swicth Spec* > > >> >>>> >>> > > >> >>>> >>> Cat3550(config)#do sh vers | i Model num|RELEA > > >> >>>> >>> Cisco IOS Software, C3550 Software (C3550-IPSERVICESK9-M), > > Version > > >> >>>> >>> 12.2(44)SE3, RELEASE SOFTWARE (fc2) > > >> >>>> >>> Model number: WS-C3550-24-SMI > > >> >>>> >>> * > > >> >>>> >>> * > > >> >>>> >>> *2811 Router Spec* > > >> >>>> >>> > > >> >>>> >>> Router(config)#do sh ver | i image > > >> >>>> >>> System image file is > > >> >>>> "flash:c2800nm-adventerprisek9-mz.124-24.T2.bin" > > >> >>>> >>> * > > >> >>>> >>> * > > >> >>>> >>> *3825 Router Spec* > > >> >>>> >>> * > > >> >>>> >>> * > > >> >>>> >>> R3825(config-subif)#do sh ver | i Software > > >> >>>> >>> Cisco IOS Software, 3800 Software (C3825-ADVENTERPRISEK9-M), > > >> Version > > >> >>>> >>> 12.4(24)T2, RELEASE SOFTWARE (fc2) > > >> >>>> >>> > > >> >>>> >>> *2811 (for vlan 10 ) Router Spec * > > >> >>>> >>> * > > >> >>>> >>> * > > >> >>>> > > >> >>>> >>> R2811-forvlan10(config)#do sh ver | i Software > > >> >>>> >>> Cisco IOS Software, 2800 Software > (C2800NM-ADVENTERPRISEK9-M), > > >> >>>> Version > > >> >>>> >>> 12.4(24)T2, RELEASE SOFTWARE (fc2) > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> *CDP *(so we have Fas 0/1 connected to 2811and we have Gig > > 0/2 > > >> >>>> > > >> >>>> >>> connected to 3825 and Fa0/4 Connected to R2811-forvlan10) > > >> >>>> >>> > > >> >>>> >>> Cat3550(config-if)#do sh cdp nei | i R2811|R3825|ID > > >> >>>> >>> Device ID Local Intrfce Holdtme Capability > > Platform > > >> >>>> Port > > >> >>>> >>> ID > > >> >>>> >>> R2811-forvlan10 Fas 0/4 123 R S I > 2811 > > >> >>>> Fas > > >> >>>> >>> 0/0 > > >> >>>> >>> R2811 Fas 0/1 139 R S I > 2811 > > >> >>>> Fas > > >> >>>> >>> 0/0 > > >> >>>> >>> R3825 Gig 0/2 129 R S I > 3825 > > >> >>>> Gig > > >> >>>> >>> 0/0 > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> *INTERFACE CONFIG* > > >> >>>> >>> * > > >> >>>> >>> * > > >> >>>> >>> Cat3550(config-if)#do sh run int *fa0/1* > > >> >>>> >>> interface FastEthernet0/1 > > >> >>>> >>> description *TRUNK to R2811* > > >> >>>> >>> switchport trunk encapsulation dot1q > > >> >>>> >>> switchport trunk native vlan 10 > > >> >>>> >>> switchport mode trunk > > >> >>>> >>> end > > >> >>>> >>> > > >> >>>> >>> Cat3550(config-if)#do sh run int fa0/4 > > >> >>>> >>> interface FastEthernet0/4 > > >> >>>> >>> description *ACCESS LINK TO R2811-forvlan10* > > >> >>>> > > >> >>>> >>> switchport access vlan 10 > > >> >>>> >>> switchport mode access > > >> >>>> >>> end > > >> >>>> >>> > > >> >>>> >>> Cat3550(config-if)#do sh run int gi0/2 > > >> >>>> >>> interface GigabitEthernet0/2 > > >> >>>> >>> description *TRUNK to R3825* > > >> >>>> > > >> >>>> >>> switchport trunk encapsulation dot1q > > >> >>>> >>> switchport trunk native vlan 10 > > >> >>>> >>> switchport mode trunk > > >> >>>> >>> end > > >> >>>> >>> > > >> >>>> >>> Cat3550(config-if)#do sh run int vlan 10 > > >> >>>> >>> interface Vlan10 > > >> >>>> >>> ip address 10.1.1.2 255.255.255.0 > > >> >>>> >>> end > > >> >>>> >>> > > >> >>>> >>> Cat3550(config-if)#do sh int status > > >> >>>> >>> Port Name Status Vlan Duplex > > Speed > > >> >>>> Type > > >> >>>> >>> Fa0/1 TRUNK to R2811 connected trunk a-full > > a-100 > > >> >>>> >>> 10/100BaseTX > > >> >>>> >>> Fa0/4 ACCESS LINK TO R28 connected 10 a-full > > a-100 > > >> >>>> >>> 10/100Base > > >> >>>> >>> Gi0/2 TRUNK to R3825 connected trunk a-full > > a-1000 > > >> >>>> >>> 1000BaseSX > > >> >>>> >>> > > >> >>>> >>> *VLANS* > > >> >>>> >>> * > > >> >>>> > > >> >>>> >>> * > > >> >>>> >>> VLAN Name Status Ports > > >> >>>> >>> ---- -------------------------------- --------- > > >> >>>> >>> ------------------------------- > > >> >>>> >>> 1 default active Fa0/2, Fa0/3, > > >> Fa0/5, > > >> >>>> >>> Fa0/6 > > >> >>>> >>> Fa0/7, Fa0/8, > > >> Fa0/9, > > >> >>>> >>> Fa0/10 > > >> >>>> >>> Fa0/11, > Fa0/12, > > >> >>>> Fa0/13, > > >> >>>> >>> Fa0/14 > > >> >>>> >>> Fa0/15, > Fa0/16, > > >> >>>> Fa0/17, > > >> >>>> >>> Fa0/18 > > >> >>>> >>> Gi0/1 > > >> >>>> >>> 10 VLAN0010 active Fa0/4 > > >> >>>> >>> 20 VLAN0020 active > > >> >>>> >>> 30 VLAN0030 active > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> R2811(config-subif)#do sh run int fa0/0.1 > > >> >>>> >>> interface FastEthernet0/0.1 > > >> >>>> >>> description "MISMATCHED NATIVE VLAN 20/10" > > >> >>>> >>> encapsulation dot1Q 20 native > > >> >>>> >>> ip address 10.1.1.1 255.255.255.0 > > >> >>>> >>> end > > >> >>>> >>> > > >> >>>> >>> R3825(config-subif)#do sh run int gi0/0.1 > > >> >>>> >>> interface GigabitEthernet0/0.1 > > >> >>>> >>> description "MISMATCHED NATIVE VLAN 30/10" > > >> >>>> >>> encapsulation dot1Q 30 native > > >> >>>> >>> ip address 10.1.1.3 255.255.255.0 > > >> >>>> >>> end > > >> >>>> >>> > > >> >>>> >>> R2811-forvlan10(config-if)#do sh run int fa0/0 > > >> >>>> >>> interface FastEthernet0/0 > > >> >>>> >>> description "THIS ONE IS AN ACCESS LINK WHICH WE WILL PUT IN > > VLAN > > >> >>>> 10 ON > > >> >>>> >>> THE SWITCH" > > >> >>>> >>> ip address 10.1.1.4 255.255.255.0 > > >> >>>> >>> duplex auto > > >> >>>> >>> speed auto > > >> >>>> >>> end > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> Cat3550(config-if)#do ping 10.1.1.255 > > >> >>>> >>> Type escape sequence to abort. > > >> >>>> >>> Sending 5, 100-byte ICMP Echos to 10.1.1.255, timeout is 2 > > >> seconds: > > >> >>>> >>> Reply to request 0 from 10.1.1.3, 1 ms > > >> >>>> >>> Reply to request 0 from 10.1.1.1, 1 ms > > >> >>>> >>> Reply to request 0 from 10.1.1.4, 1 ms > > >> >>>> >>> > > >> >>>> >>> R2811(config-subif)#do ping 10.1.1.255 > > >> >>>> >>> Type escape sequence to abort. > > >> >>>> >>> Sending 5, 100-byte ICMP Echos to 10.1.1.255, timeout is 2 > > >> seconds: > > >> >>>> >>> Reply to request 0 from 10.1.1.3, 1 ms > > >> >>>> >>> Reply to request 0 from 10.1.1.2, 1 ms > > >> >>>> >>> Reply to request 0 from 10.1.1.4, 1 ms > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> R3825(config-subif)#do ping 10.1.1.255 > > >> >>>> >>> Type escape sequence to abort. > > >> >>>> >>> Sending 5, 100-byte ICMP Echos to 10.1.1.255, timeout is 2 > > >> seconds: > > >> >>>> >>> Reply to request 0 from 10.1.1.2, 4 ms > > >> >>>> >>> Reply to request 0 from 10.1.1.1, 4 ms > > >> >>>> >>> Reply to request 1 from 10.1.1.2, 1 ms > > >> >>>> >>> Reply to request 1 from 10.1.1.1, 1 ms > > >> >>>> >>> Reply to request 1 from 10.1.1.4, 1 ms > > >> >>>> >>> > > >> >>>> >>> R2811-forvlan10(config-if)#do ping 10.1.1.255 > > >> >>>> >>> > > >> >>>> >>> Type escape sequence to abort. > > >> >>>> >>> Sending 5, 100-byte ICMP Echos to 10.1.1.255, timeout is 2 > > >> seconds: > > >> >>>> >>> > > >> >>>> >>> Reply to request 0 from 10.1.1.3, 4 ms > > >> >>>> >>> Reply to request 0 from 10.1.1.1, 4 ms > > >> >>>> >>> Reply to request 0 from 10.1.1.2, 4 ms > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> *CONCLUSION: So we have full reachability despite the vlan > > >> >>>> mismatch.* > > >> >>>> > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> Olugbenga Oyebande > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>>> On Fri, Dec 9, 2011 at 7:38 PM, Oluwagbenga Oyebande < > > >> >>>> >>>> [email protected]> wrote: > > >> >>>> >>>> > > >> >>>> >>>>> Hi CCIE Kid > > >> >>>> >>>>> > > >> >>>> >>>>> I agree with Narottam. I would like to add something to Q2 > > >> >>>> >>>>> > > >> >>>> >>>>> > > >> >>>> >>>>> Answ to Q1. The trunk will form as you have already seen. > > >> >>>> >>>>> > > >> >>>> >>>>> Answ to Q2. If by user traffic you mean IP traffic, then > the > > >> >>>> answer > > >> >>>> >>>>> depends on the IP configuration of your switch's *VLAN 10 > > SVI. > > >> *If > > >> >>>> > > >> >>>> >>>>> you have 10.1.1.0/24 subnet configured on the switch's SVI > > >> then > > >> >>>> IP > > >> >>>> >>>>> traffic should pass in spite of native vlan mismatch. If > you > > >> have > > >> >>>> another > > >> >>>> >>>>> subnet (or no ip address) configured on it then IP traffic > > will > > >> >>>> not pass. > > >> >>>> >>>>> * > > >> >>>> > > >> >>>> >>>>> * > > >> >>>> >>>>> > > >> >>>> >>>>> > > >> >>>> >>>>> On Fri, Dec 9, 2011 at 7:45 AM, Narottam Prajapati < > > >> >>>> >>>>> [email protected]> wrote: > > >> >>>> >>>>> > > >> >>>> >>>>>> HI > > >> >>>> >>>>>> > > >> >>>> >>>>>> Native VLAN numbering mismatch will not affect to > trunk > > >> >>>> forming > > >> >>>> >>>>>> process. Trunk will form between both devics. > > >> >>>> >>>>>> > > >> >>>> >>>>>> Regarding Traffic forwarding traffic will forward without > > any > > >> >>>> tagigng > > >> >>>> >>>>>> due > > >> >>>> >>>>>> to default behaviour of dot1q encapsulation. > > >> >>>> >>>>>> > > >> >>>> >>>>>> When router try to forward traffic to switch frames > > forwards up > > >> >>>> to > > >> >>>> >>>>>> switch > > >> >>>> >>>>>> and switch 2 assume that this traffic is for native VLAN > > >> traffic > > >> >>>> >>>>>> because > > >> >>>> >>>>>> frames are untaged. > > >> >>>> >>>>>> > > >> >>>> >>>>>> Hi Group > > >> >>>> >>>>>> > > >> >>>> >>>>>> make me correct if any thing is wrong. > > >> >>>> >>>>>> > > >> >>>> >>>>>> Regards, > > >> >>>> >>>>>> Narottam Prajapati > > >> >>>> >>>>>> > > >> >>>> >>>>>> On Fri, Dec 9, 2011 at 11:25 AM, Shaughn Smith < > > >> >>>> [email protected]> > > >> >>>> >>>>>> wrote: > > >> >>>> >>>>>> > > >> >>>> >>>>>> > Your question was answered. A few times. > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > CCIE # 23962 (SP) > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > Sent from my iPhone 4 > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > On 09 Dec 2011, at 7:40 AM, CCIE KID < > [email protected] > > > > > >> >>>> wrote: > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > > Hi all, > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > Still my question has not been answered. What will > > happen > > >> if > > >> >>>> a > > >> >>>> >>>>>> router > > >> >>>> >>>>>> > > connected to a switch is placed in two different > native > > >> >>>> Vlans. U > > >> >>>> >>>>>> guys are > > >> >>>> >>>>>> > > all talking about connecting two switches and > > incorporating > > >> >>>> two > > >> >>>> >>>>>> different > > >> >>>> >>>>>> > > native vlans. > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > My scenario is simple. R1-----------------------Sw1 > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > I m using two different native vlans from R1 to Sw1 . > > >> Whether > > >> >>>> >>>>>> trunk will > > >> >>>> >>>>>> > > form.? Or if the trunk forms, whether user traffic > > will be > > >> >>>> able > > >> >>>> >>>>>> to pass > > >> >>>> >>>>>> > > through or not. > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > Please reply to my questions > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > Thank You > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > On Fri, Dec 9, 2011 at 4:23 AM, George J. Sanchez < > > >> >>>> >>>>>> [email protected] > > >> >>>> >>>>>> > >wrote: > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > >> I've seen plenty of customers networks with native > vlan > > >> >>>> >>>>>> mismatches, > > >> >>>> >>>>>> > >> traffic will pass. With that being said, newer code > > may > > >> fix > > >> >>>> >>>>>> different > > >> >>>> >>>>>> > >> "features" that previous codes had issues with. > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> Regards, > > >> >>>> >>>>>> > >> Joe Sanchez > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> On Dec 8, 2011, at 1:28 PM, Narbik Kocharians < > > >> >>>> [email protected] > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > wrote: > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >>> This is what i was referring to: > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> R1 s F0/0 is connected to SW1 s port F0/1 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> R2 s F0/1 is connected to SW2 s port F0/2 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> SW1 s F0/19 is connected to SW2 s F0/19 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> *SW1#sh run int f0/19 | B inter* > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> interface FastEthernet0/19 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> switchport trunk encapsulation dot1q > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> switchport trunk native vlan 10 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> switchport mode trunk > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> end > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> * > > >> >>>> >>>>>> > >>> * > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> *SW2#sh run int f0/19 | B inter* > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> interface FastEthernet0/19 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> switchport trunk encapsulation dot1q > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> switchport mode trunk > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> end > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> *NOTE: The trunk is UP* > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> *SW1#Show int trunk* > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Port Mode Encapsulation Status > > >> >>>> Native > > >> >>>> >>>>>> vlan > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Fa0/19 on 802.1q trunking > > 10 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Port Vlans allowed on trunk > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Fa0/19 1-4094 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Port Vlans allowed and active in management > > domain > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Fa0/19 1,10,80 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Port Vlans in spanning tree forwarding state > > and > > >> not > > >> >>>> >>>>>> pruned > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Fa0/19 1,10,80 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> *SW2#sh spanning-tree blockedports * > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Name Blocked Interfaces List > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> -------------------- > > ------------------------------------ > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> VLAN0001 Fa0/19 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> VLAN0010 Fa0/19 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Number of blocked ports (segments) in the system : 2 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> *All Traffic is blocked for the two Vlans.* > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> *And sure you can get around it, and one way to do > > this > > >> is > > >> >>>> to > > >> >>>> >>>>>> filter > > >> >>>> >>>>>> > >> BPDUs > > >> >>>> >>>>>> > >>> that carry the VLANs as you mentioned:* > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> SW1(config)#int f0/19 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> SW1(config-if)#spanning-tree bpdufilter en > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> *SW1#sh spannin blockedports * > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Name Blocked Interfaces List > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> -------------------- > > ------------------------------------ > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Number of blocked ports (segments) in the system : 0 > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> *And I am sure there are other ways. But remember > > this is > > >> >>>> the > > >> >>>> >>>>>> default > > >> >>>> >>>>>> > >>> behavior BUT not on all IOSes, on some IOSes, it > will > > >> >>>> complain > > >> >>>> >>>>>> that > > >> >>>> >>>>>> > there > > >> >>>> >>>>>> > >>> is a Native VLAN mismatch, but it will NOT block the > > >> VLANs > > >> >>>> >>>>>> configured > > >> >>>> >>>>>> > as > > >> >>>> >>>>>> > >>> Native* > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> On Thu, Dec 8, 2011 at 10:35 AM, Narbik Kocharians < > > >> >>>> >>>>>> [email protected] > > >> >>>> >>>>>> > >>> wrote: > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>>> Yes, you are correct, you can get around it, i was > > >> >>>> referring > > >> >>>> >>>>>> to the > > >> >>>> >>>>>> > >>>> default behavior. > > >> >>>> >>>>>> > >>>> > > >> >>>> >>>>>> > >>>> > > >> >>>> >>>>>> > >>>> On Thu, Dec 8, 2011 at 9:23 AM, Paul Cocker < > > >> >>>> >>>>>> [email protected]> > > >> >>>> >>>>>> > >> wrote: > > >> >>>> >>>>>> > >>>> > > >> >>>> >>>>>> > >>>>> Spanning-tree... > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> I'm guessing the vlan is in the bpdu. > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> with this config... > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> SW1 > > >> >>>> >>>>>> > >>>>> interface FastEthernet0/13 > > >> >>>> >>>>>> > >>>>> switchport trunk encapsulation dot1q > > >> >>>> >>>>>> > >>>>> switchport trunk native vlan 10 > > >> >>>> >>>>>> > >>>>> switchport mode trunk > > >> >>>> >>>>>> > >>>>> switchport nonegotiate > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> SW2 > > >> >>>> >>>>>> > >>>>> interface FastEthernet0/13 > > >> >>>> >>>>>> > >>>>> switchport access vlan 20 > > >> >>>> >>>>>> > >>>>> switchport trunk encapsulation dot1q > > >> >>>> >>>>>> > >>>>> switchport trunk native vlan 20 > > >> >>>> >>>>>> > >>>>> switchport mode trunk > > >> >>>> >>>>>> > >>>>> switchport nonegotiate > > >> >>>> >>>>>> > >>>>> no cdp enable > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> you get this... > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> *Mar 1 00:18:26.994: %SPANTREE-2-RECV_PVID_ERR: > > >> Received > > >> >>>> >>>>>> BPDU with > > >> >>>> >>>>>> > >>>>> inconsistent peer vlan id 10 on FastEthernet0/13 > > >> VLAN20. > > >> >>>> >>>>>> > >>>>> *Mar 1 00:18:26.994: > %SPANTREE-2-BLOCK_PVID_LOCAL: > > >> >>>> Blocking > > >> >>>> >>>>>> > >>>>> FastEthernet0/13 on VLAN0020. Inconsistent local > > vlan. > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> You can disable spanning tree, or use bpdufilter > to > > get > > >> >>>> >>>>>> around it. > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> On 08/12/2011 16:58, Carlos G Mendioroz wrote: > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>>> What mechanism is responsible for such blocking ? > > >> >>>> >>>>>> > >>>>>> > > >> >>>> >>>>>> > >>>>>> -Carlos > > >> >>>> >>>>>> > >>>>>> > > >> >>>> >>>>>> > >>>>>> Narbik Kocharians @ 08/12/2011 13:34 -0300 dixit: > > >> >>>> >>>>>> > >>>>>> > > >> >>>> >>>>>> > >>>>>>> Between any two switch if the Native VLAN is > > >> >>>> mismatched the > > >> >>>> >>>>>> trunk > > >> >>>> >>>>>> > >> will > > >> >>>> >>>>>> > >>>>>>> come up but you won't be able to pass any > traffic > > >> >>>> through > > >> >>>> >>>>>> it, and > > >> >>>> >>>>>> > you > > >> >>>> >>>>>> > >>> can > > >> >>>> >>>>>> > >>>>>>> see that with a "Show spanning block". > > >> >>>> >>>>>> > >>>>>>> On Thu, Dec 8, 2011 at 4:31 AM, David Bass > > >> >>>> >>>>>> > >>> <[email protected]<mailto: > > >> >>>> >>>>>> > >>>>>>> [email protected]**>> wrote: > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> We are talking about CCIE lab, so best practice > > and > > >> >>>> >>>>>> "working" > > >> >>>> >>>>>> > >> status > > >> >>>> >>>>>> > >>>>>>> all go out the window :). In his scenario he's > > >> >>>> talking > > >> >>>> >>>>>> about > > >> >>>> >>>>>> > >> router > > >> >>>> >>>>>> > >>>>>>> to switch trunk, so no VTP or STP (if you do > this > > >> >>>> switch > > >> >>>> >>>>>> to switch > > >> >>>> >>>>>> > >>>>>>> you'll definitely have issues though, so very > > good > > >> to > > >> >>>> >>>>>> know)...CDP > > >> >>>> >>>>>> > >>>>>>> will definitely bark non-stop though which is > > very > > >> >>>> >>>>>> irritating. > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> On Dec 8, 2011, at 6:08 AM, Carlos G Mendioroz > > >> wrote: > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>>> May be depending on the equipment, the trunk > will > > >> >>>> "form" > > >> >>>> >>>>>> just > > >> >>>> >>>>>> > fine, > > >> >>>> >>>>>> > >>>>>>>> if VLAN hopping is not considered to be a > > problem :) > > >> >>>> >>>>>> > >>>>>>>> CDP may barf. If VLAN 1 is involved, other > griefs > > >> >>>> will pop. > > >> >>>> >>>>>> > >>>>>>>> > > >> >>>> >>>>>> > >>>>>>>> Different problems: > > >> >>>> >>>>>> > >>>>>>>> -framing: no problem, but "native VLAN" frames > do > > >> not > > >> >>>> >>>>>> signal > > >> >>>> >>>>>> > >>>>>>> which VLAN > > >> >>>> >>>>>> > >>>>>>>> they belong to, so if they do not match, frames > > will > > >> >>>> hop > > >> >>>> >>>>>> from one > > >> >>>> >>>>>> > >>>>>>> VLAN > > >> >>>> >>>>>> > >>>>>>>> to the other. > > >> >>>> >>>>>> > >>>>>>>> > > >> >>>> >>>>>> > >>>>>>>> -signalling (DTP): AFAIK, VLANs are not part of > > the > > >> >>>> info > > >> >>>> >>>>>> > >>>>>>> interchanged, so the trunk will form even if > > native > > >> >>>> is not > > >> >>>> >>>>>> the > > >> >>>> >>>>>> > >> same. > > >> >>>> >>>>>> > >>>>>>>> > > >> >>>> >>>>>> > >>>>>>>> -control: (CDP/VTP/STP/...): well, you may > have a > > >> >>>> problem > > >> >>>> >>>>>> here. > > >> >>>> >>>>>> > >>>>>>>> In particular, CDP/VTP go on VLAN 1, so if this > > is > > >> >>>> one of > > >> >>>> >>>>>> the > > >> >>>> >>>>>> > VLANs > > >> >>>> >>>>>> > >>>>>>>> involved in the crossing, it won't work. > > >> >>>> >>>>>> > >>>>>>>> > > >> >>>> >>>>>> > >>>>>>>> -Others ? > > >> >>>> >>>>>> > >>>>>>>> > > >> >>>> >>>>>> > >>>>>>>> -Carlos > > >> >>>> >>>>>> > >>>>>>>> > > >> >>>> >>>>>> > >>>>>>>> > > >> >>>> >>>>>> > >>>>>>>> David Bass @ 08/12/2011 08:25 -0300 dixit: > > >> >>>> >>>>>> > >>>>>>>>> The trunk will come up fine, but you won't > have > > IP > > >> >>>> >>>>>> connectivity > > >> >>>> >>>>>> > >>>>>>> between the 2 devices on the VLANs/subnets you > > are > > >> >>>> >>>>>> expecting > > >> >>>> >>>>>> > >> because > > >> >>>> >>>>>> > >>>>>>> the 2 native VLANs are being bridged. Do some > > >> >>>> research on > > >> >>>> >>>>>> how > > >> >>>> >>>>>> > >> dot1q > > >> >>>> >>>>>> > >>>>>>> trunks work and you should be able to figure it > > out. > > >> >>>> On > > >> >>>> >>>>>> Dec 7, > > >> >>>> >>>>>> > >> 2011, > > >> >>>> >>>>>> > >>>>>>> at 11:40 PM, CCIE KID <[email protected] > > >> >>>> >>>>>> > >>>>>>> <mailto:[email protected]>> wrote: > > >> >>>> >>>>>> > >>>>>>>>>> Hi fellas, > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> I tested a scenario where the Native vlan > > differs > > >> >>>> from > > >> >>>> >>>>>> the > > >> >>>> >>>>>> > >>>>>>> router port to > > >> >>>> >>>>>> > >>>>>>>>>> the switch port. I understood that if the > > NAtive > > >> >>>> vlan > > >> >>>> >>>>>> > >>>>>>> mismatches on a trunk > > >> >>>> >>>>>> > >>>>>>>>>> port , then appropriate trunking wont be > > formed. > > >> >>>> >>>>>> > >>>>>>>>>> But when i connect my router to a switch and > in > > >> the > > >> >>>> >>>>>> router > > >> >>>> >>>>>> > >>>>>>> subinterface . I > > >> >>>> >>>>>> > >>>>>>>>>> am having a native vlan of 20 and in the > switch > > >> >>>> port it > > >> >>>> >>>>>> is > > >> >>>> >>>>>> > >>>>>>> having a native > > >> >>>> >>>>>> > >>>>>>>>>> vlan of 10 , but still the trunk is forming > > >> >>>> perfectly > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> Can someone correct me > > >> >>>> >>>>>> > >>>>>>>>>> fa0/1.1 > > >> >>>> fa0/1 > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > > Router1-----------------------**------------------------Switch > > >> 1 > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> Router 1 > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> inter fa 0/1.1 > > >> >>>> >>>>>> > >>>>>>>>>> encap dot1q 20 native > > >> >>>> >>>>>> > >>>>>>>>>> ip add 10.1.1.1 255.255.255.0 > > >> >>>> >>>>>> > >>>>>>>>>> no sh > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> Switch 1 > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> int fa 0/1 > > >> >>>> >>>>>> > >>>>>>>>>> enc dot1q 10 native > > >> >>>> >>>>>> > >>>>>>>>>> swi trunk enc dot > > >> >>>> >>>>>> > >>>>>>>>>> swi mo trunk > > >> >>>> >>>>>> > >>>>>>>>>> no sh > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> But s > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> -- > > >> >>>> >>>>>> > >>>>>>>>>> With Warmest Regards, > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> CCIE KID > > >> >>>> >>>>>> > >>>>>>>>>> CCIE#29992 (Security) > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> Blogs and organic groups at > > http://www.ccie.net > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > > >> ______________________________**______________________________** > > >> >>>> >>>>>> > >>>>>>> ___________ > > >> >>>> >>>>>> > >>>>>>>>>> Subscription information may be found at: > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>> http://www.groupstudy.com/**list/CCIELab.html< > > >> >>>> >>>>>> > >> http://www.groupstudy.com/list/ > > >> >>>> >>>>>> > >>> CCIELab.html> > > >> >>>> >>>>>> > >>>>>>>>> Blogs and organic groups at > http://www.ccie.net > > >> >>>> >>>>>> > >>>>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > > >> ______________________________**______________________________** > > >> >>>> >>>>>> > >>>>>>> ___________ > > >> >>>> >>>>>> > >>>>>>>>> Subscription information may be found at: > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>> http://www.groupstudy.com/**list/CCIELab.html< > > >> >>>> >>>>>> > >> http://www.groupstudy.com/list/ > > >> >>>> >>>>>> > >>> CCIELab.html> > > >> >>>> >>>>>> > >>>>>>>> > > >> >>>> >>>>>> > >>>>>>>> -- > > >> >>>> >>>>>> > >>>>>>>> Carlos G Mendioroz <[email protected] <mailto: > > >> >>>> >>>>>> [email protected]>> > > >> >>>> >>>>>> > >>>>>>> LW7 EQI Argentina > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> Blogs and organic groups at > http://www.ccie.net > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > > >> ______________________________**______________________________** > > >> >>>> >>>>>> > >>>>>>> ___________ > > >> >>>> >>>>>> > >>>>>>> Subscription information may be found at: > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>> http://www.groupstudy.com/**list/CCIELab.html< > > >> >>>> >>>>>> > >> http://www.groupstudy.com/list/ > > >> >>>> >>>>>> > >>> CCIELab.html> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>>> -- > > >> >>>> >>>>>> > >>>>>>> *Narbik Kocharians > > >> >>>> >>>>>> > >>>>>>> *CCSI#30832, CCIE# 12410 (R&S, SP, Security) > > >> >>>> >>>>>> > >>>>>>> *www.MicronicsTraining.com* > > >> >>>> >>>>>> > >>> <http://www.micronicstraining.**com/< > > >> >>>> >>>>>> http://www.micronicstraining.com/ > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > >>>>>>>> > > >> >>>> >>>>>> > >>>>>>> Sr. Technical Instructor > > >> >>>> >>>>>> > >>>>>>> YES! We take Cisco Learning Credits! > > >> >>>> >>>>>> > >>>>>>> Training & Remote Racks available > > >> >>>> >>>>>> > >>>>>>> > > >> >>>> >>>>>> > >>>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> Blogs and organic groups at http://www.ccie.net > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > > >> ______________________________**______________________________** > > >> >>>> >>>>>> > >>>>> ___________ > > >> >>>> >>>>>> > >>>>> Subscription information may be found at: > > >> >>>> >>>>>> > http://www.groupstudy.com/** > > >> >>>> >>>>>> > >>>>> list/CCIELab.html < > > >> >>>> >>>>>> http://www.groupstudy.com/list/CCIELab.html> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>>> > > >> >>>> >>>>>> > >>>> > > >> >>>> >>>>>> > >>>> > > >> >>>> >>>>>> > >>>> -- > > >> >>>> >>>>>> > >>>> *Narbik Kocharians > > >> >>>> >>>>>> > >>>> * > > >> >>>> >>>>>> > >>>> CCSI#30832, CCIE# 12410 (R&S, SP, Security) > > >> >>>> >>>>>> > >>>> *www.MicronicsTraining.com* < > > >> >>>> http://www.micronicstraining.com/ > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > >>>> Sr. Technical Instructor > > >> >>>> >>>>>> > >>>> YES! We take Cisco Learning Credits! > > >> >>>> >>>>>> > >>>> Training & Remote Racks available > > >> >>>> >>>>>> > >>>> > > >> >>>> >>>>>> > >>>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> -- > > >> >>>> >>>>>> > >>> *Narbik Kocharians > > >> >>>> >>>>>> > >>> *CCSI#30832, CCIE# 12410 (R&S, SP, Security) > > >> >>>> >>>>>> > >>> *www.MicronicsTraining.com* < > > >> >>>> http://www.micronicstraining.com/> > > >> >>>> >>>>>> > >>> Sr. Technical Instructor > > >> >>>> >>>>>> > >>> YES! We take Cisco Learning Credits! > > >> >>>> >>>>>> > >>> Training & Remote Racks available > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> Blogs and organic groups at http://www.ccie.net > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > >>> > > >> >>>> >>>>>> > > >> >>>> > > >> > _______________________________________________________________________ > > >> >>>> >>>>>> > >>> Subscription information may be found at: > > >> >>>> >>>>>> > >>> http://www.groupstudy.com/list/CCIELab.html > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> Blogs and organic groups at http://www.ccie.net > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > > >> >>>> > > >> > _______________________________________________________________________ > > >> >>>> >>>>>> > >> Subscription information may be found at: > > >> >>>> >>>>>> > >> http://www.groupstudy.com/list/CCIELab.html > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > >> > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > -- > > >> >>>> >>>>>> > > With Warmest Regards, > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > CCIE KID > > >> >>>> >>>>>> > > CCIE#29992 (Security) > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > Blogs and organic groups at http://www.ccie.net > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > > > >> >>>> >>>>>> > > >> >>>> > > >> > _______________________________________________________________________ > > >> >>>> >>>>>> > > Subscription information may be found at: > > >> >>>> >>>>>> > > http://www.groupstudy.com/list/CCIELab.html > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > Blogs and organic groups at http://www.ccie.net > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > > > >> >>>> >>>>>> > > >> >>>> > > >> > _______________________________________________________________________ > > >> >>>> >>>>>> > Subscription information may be found at: > > >> >>>> >>>>>> > http://www.groupstudy.com/list/CCIELab.html > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> >>>>>> Blogs and organic groups at http://www.ccie.net > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> > > >> > _______________________________________________________________________ > > >> >>>> >>>>>> Subscription information may be found at: > > >> >>>> >>>>>> http://www.groupstudy.com/list/CCIELab.html > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> >>>>>> > > >> >>>> >>>>> > > >> >>>> >>>>> > > >> >>>> >>>>> -- > > >> >>>> >>>>> -- > > >> >>>> >>>>> Olugbenga Oyebande > > >> >>>> >>>>> MD, DAIT > > >> >>>> >>>>> 234-803-302-5287 > > >> >>>> >>>>> http://www.dait-ng.com > > >> >>>> >>>>> Cisco Unified Network, VPN > > >> >>>> >>>>> DAIT Enterprise Network Servers > > >> >>>> >>>>> Broadband Internet Deployment & ISP Consultancy > > >> >>>> >>>>> > > >> >>>> >>>>> > > >> >>>> >>>> > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >>> -- > > >> >>>> >>> -- > > >> >>>> >>> Olugbenga Oyebande > > >> >>>> >>> MD, DAIT > > >> >>>> >>> 234-803-302-5287 > > >> >>>> >>> http://www.dait-ng.com > > >> >>>> >>> Cisco Unified Network, VPN > > >> >>>> >>> DAIT Enterprise Network Servers > > >> >>>> >>> Broadband Internet Deployment & ISP Consultancy > > >> >>>> >>> > > >> >>>> >>> > > >> >>>> >> > > >> >>>> >> > > >> >>>> >> -- > > >> >>>> >> With Warmest Regards, > > >> >>>> >> > > >> >>>> >> CCIE KID > > >> >>>> >> CCIE#29992 (Security) > > >> >>>> >> > > >> >>>> >> > > >> >>>> >> > > >> >>>> > > > >> >>>> > > >> >>>> > > >> >>>> -- > > >> >>>> With Warmest Regards, > > >> >>>> > > >> >>>> CCIE KID > > >> >>>> CCIE#29992 (Security) > > >> >>>> _______________________________________________ > > >> >>>> For more information regarding industry leading CCIE Lab > training, > > >> >>>> please visit www.ipexpert.com > > >> >>>> > > >> >>>> Are you a CCNP or CCIE and looking for a job? Check out > > >> >>>> www.PlatinumPlacement.com > > >> >>>> > > >> >>>> http://onlinestudylist.com/mailman/listinfo/ccie_rs > > >> >>>> > > >> >>> > > >> >>> > > >> >> > > >> >> > > >> >> -- > > >> >> With Warmest Regards, > > >> >> > > >> >> CCIE KID > > >> >> CCIE#29992 (Security) > > >> >> > > >> >> > > >> >> > > >> > > > >> _______________________________________________ > > >> For more information regarding industry leading CCIE Lab training, > > please > > >> visit www.ipexpert.com > > >> > > >> Are you a CCNP or CCIE and looking for a job? Check out > > >> www.PlatinumPlacement.com > > >> > > >> http://onlinestudylist.com/mailman/listinfo/ccie_rs > > >> > > > _______________________________________________ > > > For more information regarding industry leading CCIE Lab training, > > please visit www.ipexpert.com > > > > > > Are you a CCNP or CCIE and looking for a job? Check out > > www.PlatinumPlacement.com > > > > > > http://onlinestudylist.com/mailman/listinfo/ccie_rs > > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com > > http://onlinestudylist.com/mailman/listinfo/ccie_rs > -- With Warmest Regards, CCIE KID CCIE#29992 (Security) _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
