Cool stuff Jason Maynard
________________________________ From: Tyson Scott <[email protected]> To: Marko Milivojevic <[email protected]>; ccie_rs <[email protected]> Sent: Fri, October 15, 2010 9:05:16 AM Subject: Re: [OSL | CCIE_RS] DHCP manual binding I will add just a little bit It is more specifically nulcisco-xxxx.xxxx.xxxx-interface information For instance 0063.6973.636f.2d30.3031.382e.3139.6633.2e34.3262.302d.4769.302f.30 R1#show ip dhcp binding Bindings from all pools not associated with VRF: IP address Client-ID/ Lease expiration Type Hardware address/ User name 192.168.1.4 0063.6973.636f.2d30. Oct 16 2010 11:45 AM Automatic 3031.382e.3139.6633. 2e34.3262.302d.4769. 302f.30 R1# The above string is equal to NULcisco-0018.19f3.42b0-Gi0/0 Which conforms to R2(config-if)#do sh int Gi0/0 | incl line proto|Int|bia GigabitEthernet0/0 is up, line protocol is up Hardware is BCM1125 Internal MAC, address is 0018.19f3.42b0 (bia 0018.19f3.42b0) Internet address is 192.168.1.4/24 R2(config-if)# You have to convert Hex to Characters http://www.klcconsulting.net/ascii.htm And when you add the client-id option what you are doing is getting the Cisco device to conform to the Microsoft client-identifier standard. I will admit I misunderstood this for a long time. So from Gary's example we have 0063.6973.636f.2d63.3430.312e.3032.3163.2e30.3030.312d.4661.302f.31 Which Equals NULcisco-c401.021c.0001-Fa0/1 Regards, Tyson Scott - CCIE #13513 R&S, Security, and SP Managing Partner / Sr. Instructor - IPexpert, Inc. Mailto: [email protected] Telephone: +1.810.326.1444, ext. 208 Live Assistance, Please visit: www.ipexpert.com/chat eFax: +1.810.454.0130 IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, Audio Tools, Online Hardware Rental and Classroom Training for the Cisco CCIE (R&S, Voice, Security & Service Provider) certification(s) with training locations throughout the United States, Europe, South Asia and Australia. Be sure to visit our online communities at www.ipexpert.com/communities and our public website at www.ipexpert.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Marko Milivojevic Sent: Thursday, October 14, 2010 10:46 PM To: ccie_rs Subject: Re: [OSL | CCIE_RS] DHCP manual binding So... Tyson and I had a little discussion about this. I feel almost sorry for taking it offline, but I will provide the end result. It was entertaining, as you can imagine with the two of us firing config snippets and various ways we could figure this out to each other. Almost feels like the good times when we busted that storm control myth! So, here goes... The long client-id is encoded information containing the string "cisco" followed by MAC address, followed by VLAN information. It is not option 82 as mentioned below and it's not inserted by the intermediate switch. It is option 61 (client-id), which is inserted by the client sending the discovery message. As I noted before, this option can be modified using client-id option on the client. Tyson gets round of drinks from me. He opted for special kind of cocoa, available in our Columbus classroom. Smart man - I hid a box! ;-) -- Marko Milivojevic - CCIE #18427 Senior Technical Instructor - IPexpert FREE CCIE training: http://bit.ly/vLecture Mailto: [email protected] Telephone: +1.810.326.1444 Web: http://www.ipexpert.com/ On Thu, Oct 14, 2010 at 17:15, Tyson Scott <[email protected]> wrote: > That long string has to do with option 82 insertion information. It means > the >switch is inserting this information for client to port identification. This >is >performed by default when you enable DHCP snooping on Catalyst switches. > > What are you using for switches with GNS3? Logical? real? > > Regards, > > Tyson Scott - CCIE #13513 R&S, Security, and SP > Managing Partner / Sr. Instructor - IPexpert, Inc. > Mailto: [email protected] > Telephone: +1.810.326.1444, ext. 208 > Live Assistance, Please visit: www.ipexpert.com/chat > eFax: +1.810.454.0130 > > IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, > Audio >Tools, Online Hardware Rental and Classroom Training for the Cisco CCIE (R&S, >Voice, Security & Service Provider) certification(s) with training locations >throughout the United States, Europe, South Asia and Australia. Be sure to >visit >our online communities at www.ipexpert.com/communities and our public website >at >www.ipexpert.com > > > -----Original Message----- > From: [email protected] >[mailto:[email protected]] On Behalf Of Marko Milivojevic > Sent: Thursday, October 14, 2010 2:12 PM > To: garry baker > Cc: ccie_rs > Subject: Re: [OSL | CCIE_RS] DHCP manual binding > > If you figure it out, I buy you round of drinks when we meet next time > :-). I tried anything that made sense to me and couldn't quite deduce > what it was. > > -- > Marko Milivojevic - CCIE #18427 > Senior Technical Instructor - IPexpert > > FREE CCIE training: http://bit.ly/vLecture > > Mailto: [email protected] > Telephone: +1.810.326.1444 > Web: http://www.ipexpert.com/ > > On Thu, Oct 14, 2010 at 13:07, garry baker <[email protected]> wrote: >> bingo that did it, thanks Marko... >> >> R1#debug ip dhcp server packet >> R1# >> *Mar 1 02:03:16.999: DHCPD: DHCPDISCOVER received from client >> 01c4.0102.1c00.01 on interface FastEthernet0/1. >> *Mar 1 02:03:19.767: DHCPD: DHCPDISCOVER received from client >> 01c4.0102.1c00.01 on interface FastEthernet0/1. >> *Mar 1 02:03:23.739: DHCPD: DHCPDISCOVER received from client >> 01c4.0102.1c00.01 on interface FastEthernet0/1. >> >> so where is that other long string of HEX come from, wonder why not just use >> the interface mac by default? >> >> -- >> Garry L. Baker >> >> "There is no 'patch' for stupidity." - www.sqlsecurity.com >> >> >> On Thu, Oct 14, 2010 at 11:59 AM, Marko Milivojevic <[email protected]> >> wrote: >>> >>> You will see it if you use something like this on the client: >>> >>> interface FastEthernet0/0 >>> ip address dhcp client-id FastEthernet0/0 >>> ! >>> >>> -- >>> Marko Milivojevic - CCIE #18427 >>> Senior Technical Instructor - IPexpert >>> >>> FREE CCIE training: http://bit.ly/vLecture >>> >>> Mailto: [email protected] >>> Telephone: +1.810.326.1444 >>> Web: http://www.ipexpert.com/ >>> >>> On Thu, Oct 14, 2010 at 12:44, garry baker <[email protected]> wrote: >>> > yeah i pulled up the doccd to check the "real way" to do it and it >>> > states >>> > the same as you said with the 01, that is why i was wondering about the >>> > gns3 >>> > thing, and i do not have any real routers to test on at the moment... >>> > >>> > >>> > >>>http://www.cisco.com/en/US/customer/docs/ios/ipaddr/configuration/guide/iad_dhcp_svr_cfg_ps6441_TSD_Products_Configuration_Guide_Chapter.html#wp1155880 >>> >>> > >>> > "DHCP clients require client identifiers. The unique identification of >>> > the >>> > client is specified in dotted hexadecimal notation; for example, >>> > 01b7.0813.8811.66, where 01 represents the Ethernet media type." >>> > >>> > but i didnt see that in my debug and i tried it and it did not work >>> > either >>> > on my gns3 setup that is... >>> > >>> > >>> > -- >>> > Garry L. Baker >>> > >>> > "There is no 'patch' for stupidity." - www.sqlsecurity.com >>> > >>> > >>> > On Thu, Oct 14, 2010 at 11:39 AM, Jason Maynard >>> > <[email protected]> >>> > wrote: >>> >> >>> >> interesting >>> >> Gary: I wonder what the difference is between the method you provided >>> >> and >>> >> the method I provided. >>> >> >>> >> >>> >> Jason Maynard >>> >> >>> >> ________________________________ >>> >> From: garry baker <[email protected]> >>> >> To: Aung Phyo Lwin <[email protected]> >>> >> Cc: [email protected] >>> >> Sent: Thu, October 14, 2010 12:26:36 PM >>> >> Subject: Re: [OSL | CCIE_RS] DHCP manual binding >>> >> >>> >> do a 'debug ip dhcp server packet' on the dhcp server and you will see >>> >> the >>> >> client id, not sure if it is a GNS3 thing or not, never tired it on >>> >> real >>> >> hardware... >>> >> >>> >> but i did it on GNS3 and this is how i got it to work: >>> >> >>> >> R1(dhcp server 2.2.2.1) <-> R2(client) >>> >> >>> >> R1#debug ip dhcp server packet >>> >> R1# >>> >> *Mar 1 01:19:45.635: DHCPD: DHCPDISCOVER received from client >>> >> 0063.6973.636f.2d63.3430.312e.3032.3163.2e30.3030.312d.4661.302f.31 on >>> >> interface FastEthernet0/1. >>> >> *Mar 1 01:19:48.759: DHCPD: DHCPDISCOVER received from client >>> >> 0063.6973.636f.2d63.3430.312e.3032.3163.2e30.3030.312d.4661.302f.31 on >>> >> interface FastEthernet0/1. >>> >> *Mar 1 01:19:52.883: DHCPD: DHCPDISCOVER received from client >>> >> 0063.6973.636f.2d63.3430.312e.3032.3163.2e30.3030.312d.4661.302f.31 on >>> >> interface FastEthernet0/1. >>> >> >>> >> R1#sh run | s dhcp >>> >> ip dhcp pool DHCP_POOL2 >>> >> host 2.2.2.2 255.255.255.0 >>> >> client-identifier >>> >> 0063.6973.636f.2d63.3430.312e.3032.3163.2e30.3030.312d.4661.302f.31 >>> >> client-name R2 >>> >> >>> >> R2, client debug: >>> >> R2(config-if)#do sh debug >>> >> DHCPC: >>> >> DHCP client activity debugging is on (detailed) >>> >> >>> >> R2(config-if)# >>> >> *Mar 1 01:21:32.943: DHCP: DHCP client process started: 10 >>> >> *Mar 1 01:21:32.963: RAC: Starting DHCP discover on FastEthernet0/1 >>> >> *Mar 1 01:21:32.963: DHCP: Try 1 to acquire address for >>> >> FastEthernet0/1 >>> >> *Mar 1 01:21:32.979: DHCP: allocate request >>> >> *Mar 1 01:21:32.979: DHCP: zapping entry in DHC_PURGING state for >>> >> Fa0/1 >>> >> *Mar 1 01:21:32.979: DHCP: deleting entry 660F680C 0.0.0.0 from list >>> >> *Mar 1 01:21:32.983: Temp IP addr: 0.0.0.0 for peer on Interface: >>> >> FastEthernet0/1 >>> >> *Mar 1 01:21:32.983: Temp sub net mask: 0.0.0.0 >>> >> *Mar 1 01:21:32.983: DHCP Lease server: 0.0.0.0, state: 11 Purging >>> >> *Mar 1 01:21:32.983: DHCP transaction id: 172E >>> >> *Mar 1 01:21:32.983: Lease: 0 secs, Renewal: 0 secs, Rebind: 0 >>> >> secs >>> >> *Mar 1 01:21:32.987: Next timer fires after: 00:00:20 >>> >> *Mar 1 01:21:32.987: Retry count: 0 Client-ID: >>> >> cisco-c401.021c.0001-Fa0/1 >>> >> *Mar 1 01:21:32.987: Client-ID hex dump: >>> >> 636973636F2D633430312E303231632E >>> >> *Mar 1 01:21:32.995: 303030312D4661302F31 >>> >> *Mar 1 01:21:32.999: Hostname: R2 >>> >> *Mar 1 01:21:32.999: DHCP: new entry. add to queue, interface >>> >> FastEthernet0/1 >>> >> *Mar 1 01:21:32.999: DHCP: SDiscover attempt # 1 for entry: >>> >> *Mar 1 01:21:32.999: Temp IP addr: 0.0.0.0 for peer on Interface: >>> >> FastEthernet0/1 >>> >> *Mar 1 01:21:32.999: Temp sub net mask: 0.0.0.0 >>> >> *Mar 1 01:21:33.003: DHCP Lease server: 0.0.0.0, state: 3 Selecting >>> >> *Mar 1 01:21:33.003: DHCP transaction id: 192C >>> >> *Mar 1 01:21:33.003: Lease: 0 secs, Renewal: 0 secs, Rebind: 0 >>> >> secs >>> >> *Mar 1 01:21:33.003: Next timer fires after: 00:00:04 >>> >> *Mar 1 01:21:33.007: Retry count: 1 Client-ID: >>> >> cisco-c401.021c.0001-Fa0/1 >>> >> *Mar 1 01:21:33.007: Client-ID hex dump: >>> >> 636973636F2D633430312E303231632E >>> >> *Mar 1 01:21:33.011: 303030312D4661302F31 >>> >> *Mar 1 01:21:33.015: Hostname: R2 >>> >> *Mar 1 01:21:33.015: DHCP: SDiscover: sending 291 byte length DHCP >>> >> packet >>> >> *Mar 1 01:21:33.019: DHCP: SDiscover 291 bytes >>> >> *Mar 1 01:21:33.019: B'cast on FastEthernet0/1 interface >>> >> from >>> >> 0.0.0.0 >>> >> *Mar 1 01:21:33.115: DHCP: Received a BOOTREP pkt >>> >> *Mar 1 01:21:33.115: DHCP: Scan: Message type: DHCP Offer >>> >> *Mar 1 01:21:33.119: DHCP: Scan: Server ID Option: 2.2.2.1 = 2020201 >>> >> *Mar 1 01:21:33.119: DHCP: Scan: Lease Time: 86400 >>> >> *Mar 1 01:21:33.119: DHCP: Scan: Renewal time: 43200 >>> >> *Mar 1 01:21:33.119: DHCP: Scan: Rebind time: 75600 >>> >> *Mar 1 01:21:33.119: DHCP: Scan: Subnet Address Option: 255.255.255.0 >>> >> *Mar 1 01:21:33.123: DHCP: rcvd pkt source: 2.2.2.1, destination: >>> >> 255.255.255.255 >>> >> *Mar 1 01:21:33.123: UDP sport: 43, dport: 44, length: 308 >>> >> *Mar 1 01:21:33.123: DHCP op: 2, htype: 1, hlen: 6, hops: 0 >>> >> *Mar 1 01:21:33.123: DHCP server identifier: 2.2.2.1 >>> >> *Mar 1 01:21:33.123: xid: 192C, secs: 0, flags: 8000 >>> >> *Mar 1 01:21:33.127: client: 0.0.0.0, your: 2.2.2.2 >>> >> *Mar 1 01:21:33.127: srvr: 0.0.0.0, gw: 0.0.0.0 >>> >> *Mar 1 01:21:33.127: options block length: 60 >>> >> >>> >> *Mar 1 01:21:33.127: DHCP Offer Message Offered Address: 2.2.2.2 >>> >> *Mar 1 01:21:33.131: DHCP: Lease Seconds: 86400 Renewal secs: >>> >> 43200 Rebind secs: 75600 >>> >> *Mar 1 01:21:33.131: DHCP: Server ID Option: 2.2.2.1 >>> >> *Mar 1 01:21:33.131: DHCP: offer received from 2.2.2.1 >>> >> *Mar 1 01:21:33.131: DHCP: SRequest attempt # 1 for entry: >>> >> *Mar 1 01:21:33.135: Temp IP addr: 2.2.2.2 for peer on Interface: >>> >> FastEthernet0/1 >>> >> *Mar 1 01:21:33.135: Temp sub net mask: 255.255.255.0 >>> >> *Mar 1 01:21:33.135: DHCP Lease server: 2.2.2.1, state: 4 >>> >> Requesting >>> >> *Mar 1 01:21:33.135: DHCP transaction id: 192C >>> >> *Mar 1 01:21:33.135: Lease: 86400 secs, Renewal: 0 secs, Rebind: >>> >> 0 >>> >> secs >>> >> *Mar 1 01:21:33.139: Next timer fires after: 00:00:03 >>> >> *Mar 1 01:21:33.139: Retry count: 1 Client-ID: >>> >> cisco-c401.021c.0001-Fa0/1 >>> >> *Mar 1 01:21:33.139: Client-ID hex dump: >>> >> 636973636F2D633430312E303231632E >>> >> *Mar 1 01:21:33.147: 303030312D4661302F31 >>> >> *Mar 1 01:21:33.151: Hostname: R2 >>> >> *Mar 1 01:21:33.151: DHCP: SRequest- Server ID option: 2.2.2.1 >>> >> *Mar 1 01:21:33.151: DHCP: SRequest- Requested IP addr option: 2.2.2.2 >>> >> *Mar 1 01:21:33.151: DHCP: SRequest placed lease len option: 86400 >>> >> *Mar 1 01:21:33.151: DHCP: SRequest: 309 bytes >>> >> *Mar 1 01:21:33.151: DHCP: SRequest: 309 bytes >>> >> *Mar 1 01:21:33.155: B'cast on FastEthernet0/1 interface >>> >> from >>> >> 0.0.0.0 >>> >> *Mar 1 01:21:33.303: DHCP: Received a BOOTREP pkt >>> >> *Mar 1 01:21:33.303: DHCP: Scan: Message type: DHCP Ack >>> >> *Mar 1 01:21:33.303: DHCP: Scan: Server ID Option: 2.2.2.1 = 2020201 >>> >> *Mar 1 01:21:33.307: DHCP: Scan: Lease Time: 86400 >>> >> *Mar 1 01:21:33.307: DHCP: Scan: Renewal time: 43200 >>> >> *Mar 1 01:21:33.307: DHCP: Scan: Rebind time: 75600 >>> >> *Mar 1 01:21:33.307: DHCP: Scan: Subnet Address Option: 255.255.255.0 >>> >> *Mar 1 01:21:33.311: DHCP: rcvd pkt source: 2.2.2.1, destination: >>> >> 255.255.255.255 >>> >> *Mar 1 01:21:33.311: UDP sport: 43, dport: 44, length: 308 >>> >> *Mar 1 01:21:33.311: DHCP op: 2, htype: 1, hlen: 6, hops: 0 >>> >> *Mar 1 01:21:33.311: DHCP server identifier: 2.2.2.1 >>> >> *Mar 1 01:21:33.311: xid: 192C, secs: 0, flags: 8000 >>> >> *Mar 1 01:21:33.315: client: 0.0.0.0, your: 2.2.2.2 >>> >> *Mar 1 01:21:33.315: srvr: 0.0.0.0, gw: 0.0.0.0 >>> >> *Mar 1 01:21:33.315: options block length: 60 >>> >> >>> >> *Mar 1 01:21:33.315: DHCP Ack Message >>> >> *Mar 1 01:21:33.315: DHCP: Lease Seconds: 86400 Renewal secs: >>> >> 43200 Rebind secs: 75600 >>> >> *Mar 1 01:21:33.319: DHCP: Server ID Option: 2.2.2.1 >>> >> *Mar 1 01:21:34.935: %LINK-3-UPDOWN: Interface FastEthernet0/1, >>> >> changed >>> >> state to up >>> >> *Mar 1 01:21:35.935: %LINEPROTO-5-UPDOWN: Line protocol on Interface >>> >> FastEthernet0/1, changed state to up >>> >> *Mar 1 01:21:36.339: DHCP: Releasing ipl options: >>> >> *Mar 1 01:21:36.339: DHCP: Applying DHCP options: >>> >> *Mar 1 01:21:36.339: DHCP Client Pooling: ***Allocated IP address: >>> >> 2.2.2.2 >>> >> *Mar 1 01:21:36.367: Allocated IP address = 2.2.2.2 255.255.255.0 >>> >> >>> >> *Mar 1 01:21:36.367: %DHCP-6-ADDRESS_ASSIGN: Interface FastEthernet0/1 >>> >> assigned DHCP address 2.2.2.2, mask 255.255.255.0, hostname R2 >>> >> >>> >> *Mar 1 01:21:41.075: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.1 on >>> >> FastEthernet0/1 from LOADING to FULL, Loading Done >>> >> >>> >> >>> >> R2(config-if)#do sh ip int br | i DHCP >>> >> FastEthernet0/1 2.2.2.2 YES DHCP >>> >> up u >>> >> >>> >> >>> >> >>> >> >>> >> -- >>> >> Garry L. Baker >>> >> >>> >> "There is no 'patch' for stupidity." - www.sqlsecurity.com >>> >> >>> >> >>> >> On Thu, Oct 14, 2010 at 12:57 AM, Aung Phyo Lwin >>> >> <[email protected]> >>> >> wrote: >>> >>> >>> >>> Hi All, >>> >>> >>> >>> Have someone tried manual DHCP binding on GNS3? I tired a few options >>> >>> and >>> >>> its not work. I'm not sure its because of GNS3. I think it can work on >>> >>> real >>> >>> router. Or If something I left to configure. I refer the cisco doc and >>> >>> tried >>> >>> a few option and still not work. Even I tried with setting static MAC >>> >>> on the >>> >>> client interface. I never used this option in outside environment >>> >>> as hardly >>> >>> use dhcp server on the router and if its use, just use a pool of >>> >>> address and >>> >>> dynamic mapping. >>> >>> >>> >>> (R2-dhcp-server) <-------> (client) >>> >>> >>> >>> SERVer side. >>> >>> send a client identifier in the dhcp packet >>> >>> ip dhcp pool pool1 >>> >>> host 172.16.2.254 >>> >>> client-identifier 02c7.f800.0422 >>> >>> client-name example1 >>> >>> do not send a client identifier in the DHCP >>> >>> ip dhcp pool pool2 >>> >>> host 172.16.2.253 >>> >>> hardware-address 02c7.f800.0422 ethernet >>> >>> client-name example1 >>> >>> Client Side. >>> >>> interface FastEthernet0/0 >>> >>> ip address dhcp >>> >>> duplex auto >>> >>> speed auto >>> >>> or >>> >>> interface FastEthernet0/0 >>> >>> ip dhcp client client-id ascii example1 >>> >>> ip address dhcp >>> >>> duplex auto >>> >>> speed auto >>> >>> some debug >>> >>> Client >>> >>> *Mar 1 03:00:31.639: IP: s=0.0.0.0 (local), d=255.255.255.255 >>> >>> (FastEthernet0/0), len 319, sending broad/multicast >>> >>> *Mar 1 03:00:31.639: UDP src=68, dst=67 >>> >>> Server >>> >>> *Mar 1 03:02:36.231: DHCPD: Sending notification of DISCOVER: >>> >>> *Mar 1 03:02:36.231: DHCPD: htype 1 chaddr 02c7.f800.0422 >>> >>> *Mar 1 03:02:36.231: DHCPD: remote id 020a0000c0a8010100000000 >>> >>> *Mar 1 03:02:36.231: DHCPD: circuit id 00000000 >>> >>> *Mar 1 03:02:36.231: DHCPD: DHCPDISCOVER received from client >>> >>> 0063.6973.636f.2d30.3263.372e.6638.3030.2e30.3432.322d.4661.302f.30 on >>> >>> interface FastEthernet0/0. >>> >>> *Mar 1 03:02:36.235: DHCPD: Seeing if there is an internally >>> >>> specified >>> >>> pool class: >>> >>> *Mar 1 03:02:36.235: DHCPD: htype 1 chaddr 02c7.f800.0422 >>> >>> *Mar 1 03:02:36.235: DHCPD: remote id 020a0000c0a8010100000000 >>> >>> *Mar 1 03:02:36.235: DHCPD: circuit id 00000000u all >>> >>> Regards, >>> >>> Phyo >>> >>> >>> >>> _______________________________________________ >>> >>> For more information regarding industry leading CCIE Lab training, >>> >>> please >>> >>> visit www.ipexpert.com >>> >>> >>> >> >>> > >>> > >>> > _______________________________________________ >>> > For more information regarding industry leading CCIE Lab training, >>> > please >>> > visit www.ipexpert.com >>> > >>> > >> >> >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit >www.ipexpert.com > > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
_______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
