Dual Homing to OSPF Area 0
Hi All, I ran into an interesting OSPF problem: I have multiple distribution routers (D1, D2) in OSPF area 10, dual homed to ABR's C1 and C2. C1 and C2 have a link between them, in area 0. I am doing summarization into area 0. The picture below summarizes this situation: /\ Area_0 C1 C2-^ | \ /| | | \/ | v Area_10 | / \ | | / \| D1 D2 What happens if the links between D1 & C2 and D2 & C1 fail at the same time? Communication between D1 & D2 now has to occur through C1 & C2 over area 0, which means I have segmented area 10. How is this design normally done, dual homing the "D" routers to multiple "C" routers. If the "C" routers are only ABRs for one area, does it make sense to have the link between C1 & C2 in area 10 as well? Any feedback is greatly appreciated. Thanks. AR- -- Contrary to popular belief, Unix IS user friendly. It just happens to be very selective about who it decides to make friends with. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- Andre Riscalla Network Specialist - Internet [EMAIL PROTECTED]514-940-5664 Network Engineering AT&T Canada +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: BGP question
See comments below: > I haven't worked with BGP yet, so someone please correct me if I'm wrong > with this - > > My understanding is that even if you have internet connections to two > differnet ISPs, you don't have to BGP. If you are using IP addresses they > have assigned to you then you are ok. It depends what "ok" means for you. If you need redundancy and backup, then you are not "ok". Consider the scenario below : |---| |---| |---| | | ISP1 |---| Customer |---| ISP2 | | | | | | | | AS1 | | | | AS2 | |---| |---| |---| The customer is multihomed to AS1 and AS2. The customer is not running BGP in this scenario. Suppose ISP1 has assigned the customer 10.10.10.0/24 and ISP2 has assigned the customer 10.10.11.0/24. Both ISPs are statically routing those blocks to the customer. The customer has two default routes, one to each ISP (he could prefer one ISP or the other for outbound traffic but inbound traffic will come from ISP1 or ISP2 depending on the destination ip address). Inbound traffic destined for hosts in 10.10.10.0/24 comes through ISP1 as ISP1 is originating and advertising this block. Inbound traffic destined for hosts in 10.10.11.0/24 comes through ISP2 as ISP2 is originating and advertising this block. Now what happens if the connection between the customer and ISP1 goes down for any reason ? Well you will see that hosts in 10.10.10.0/24 will be unreachable from outside the customer's network. So redundancy is not achieved properly as half of the customer's network will be down. > The big reason to use BGP would be if you have a block of registered IP > addresses and you want to advertise them to the internet via two different > ISPs. I would say that as soon as you are multihomed (to 2 different providers) then using BGP is a Must. (Of course if you really want total redundancy and the option to do intelligent routing, load-sharing..). > > > > > >Hellow group!! > >According to cisco press book, when company has two connections active to > >two different ISPs, BGP should be used. > >Could anybody tell me what is the result of connecting two active > >connections to two different ISPs? > >I know that one connection should be used as a backup line only while the > >other is active in order not to use BGP. > >Thanks in advance. > > > > > >iWon.com http://www.iwon.com why wouldn't you? > > > > > >___ > >UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > >FAQ, list archives, and subscription info: http://www.groupstudy.com > >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > -- Contrary to popular belief, Unix IS user friendly. It just happens to be very selective about who it decides to make friends with. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- Andre Riscalla Network Specialist - Internet [EMAIL PROTECTED]514-940-5664 Network Engineering AT&T Canada +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: OSPF configuration - Please help
Your OSPF config on router B is wrong : You did : router ospf 64 network 0.0.0.0 255.255.255.255 Or you should have at least something like this : router ospf 64 network 192.1.1.2 0.0.0.0 area 0 AR- On Tue, 6 Jun 2000, Billy Monroe wrote: > Hello: > > I have two 2503 and I am following Hutnik's to configure OSPF. > I connected RouterA, s0 (DCE) to RouterB, s0(DTE). > > When I enter #show ip ospf int I see the following: > ... > Transmit Delay is 1 sec, State DOWN > Hello due in... > ... > > > The State should be "POINT_TO_POINT". > The routers don't see each other. (#show ip route doesn't display OSPF > entry). > I entered "no shut" and "shut" in both routers s0 interfaces but it didn't > work. Any idea of what is wrong ? > > > Configurarion is below. > > > THanks, > > > > > > > > > > RouterA > > > ! > hostname RouterA > ! > int Loopback0 > ip add 10.1.1.1 255.255.255.0 > > > int Loopback1 > ip add 11.1.1.1 255.255.255.0 > ! > int S0 > ip add 192.1.1.1 255.255.255.0 > no fair-queue > router ospf 64 > network 192.1.1.1 0.0.0.0 area 0 > network 10.1.1.1 0.0.0.0 area 0 > ! > no ip classless > ! > ... > > > RouterB > > > ! > hostname RouterB > ! > int loopack0 > ip add 152.1.1.1 255.255.255.0 > int Loopback1 > ip add 153.1.1.1 255.255.255.0 > ! > int serial0 > ip add 192.1.1.2 255.255.255.0 > no fair-queue > clockrate 50 > ! > int s1 > no ip add > shutdown > ! > router ospf 64 > network 0.0.0.0 255.255.255.255 > ! > no ip classless > ! > ... > > > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > -- Contrary to popular belief, Unix IS user friendly. It just happens to be very selective about who it decides to make friends with. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- Andre Riscalla Network Specialist - Internet [EMAIL PROTECTED]514-940-5664 Network Engineering AT&T Canada +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Lightstream PVC config problem... [7:49352]
A couple of suggestions: 1) Verify that your ATM interfaces are up and up which i assume you already did. 2) Since your LS1010 ATM interfaces are setup with UNI version 3.1, change your ATM uni version on your routers to be 3.1. (The default is 3.0). Please provide the IOS version you are running on the LS1010 and on the routers as well. Thanks. AR- On Mon, 22 Jul 2002, Edward Sohn wrote: > Thanks for the reply, Andre... > > Hmmm...I was thinking the same way you did at first, but then the book's > configuration actually has both "atm pvc" commands in each interface. > Is that a typo, then? > > Even so, I cannot get connectivity between my routers. Here is my "sho > run" for the L1010 and 2 routers: > > L1010: > > Current configuration: > ! > version 11.2 > no service pad > no service password-encryption > no service udp-small-servers > no service tcp-small-servers > ! > hostname L1010 > ! > ! > ip host-routing > no ip domain-lookup > ! > atm address 47.0091.8100..0050.a2c6.4001.0050.a2c6.4001.00 > atm router pnni > node 1 level 56 lowest > redistribute atm-static > ! > ! > interface ATM12/0/0 > no atm auto-configuration > atm uni version 3.1 > atm maxvp-number 8 > atm maxvc-number 8192 > atm maxvpi-bits 3 > atm maxvci-bits 10 > ! > interface ATM12/0/1 > ! > interface ATM12/0/2 > no atm auto-configuration > atm uni version 3.1 > atm maxvp-number 8 > atm maxvc-number 8192 > atm maxvpi-bits 3 > atm maxvci-bits 10 > atm pvc 0 121 interface ATM12/0/0 0 112 > ! > interface ATM12/0/3 > ! > interface ATM13/0/0 > ip address 175.128.100.5 255.255.255.0 > atm maxvp-number 0 > ! > interface Ethernet13/0/0 > no ip address > ! > no ip classless > ! > line con 0 > exec-timeout 0 0 > line aux 0 > line vty 0 4 > login > ! > end > > ROUTER 1 > > Current configuration : 854 bytes > ! > version 12.2 > service timestamps debug uptime > service timestamps log uptime > no service password-encryption > ! > hostname R3620-1 > ! > ! > ip subnet-zero > ! > ! > ! > ! > ! > ! > ! > ! > ! > fax interface-type fax-mail > mta receive maximum-recipients 0 > ! > ! > ! > ! > interface FastEthernet0/0 > ip address 165.128.1.1 255.255.255.0 > duplex auto > speed auto > ! > interface Serial0/0 > no ip address > shutdown > clockrate 200 > ! > interface ATM1/0 > no ip address > no atm ilmi-keepalive > ! > interface ATM1/0.1 multipoint > ip address 165.128.100.1 255.255.255.0 > map-group ip-Pvc > atm pvc 112 0 112 aal5snap > ! > router eigrp 100 > network 165.128.0.0 > auto-summary > no eigrp log-neighbor-changes > ! > ip classless > ip http server > ! > ! > ! > map-list ip-Pvc > ip 165.128.100.2 atm-vc 112 broadcast > ! > call rsvp-sync > ! > ! > mgcp profile default > ! > dial-peer cor custom > ! > ! > ! > ! > line con 0 > line aux 0 > line vty 0 4 > ! > ! > end > > ROUTER 2: > > Current configuration : 835 bytes > ! > version 12.2 > service timestamps debug uptime > service timestamps log uptime > no service password-encryption > ! > hostname r3620-2 > ! > ! > ip subnet-zero > ! > ! > ! > ! > ! > ! > ! > ! > ! > fax interface-type fax-mail > mta receive maximum-recipients 0 > ! > ! > ! > ! > interface FastEthernet0/0 > ip address 165.128.2.2 255.255.255.0 > duplex auto > speed auto > ! > interface Serial0/0 > no ip address > shutdown > ! > interface ATM1/0 > no ip address > no atm ilmi-keepalive > ! > interface ATM1/0.1 multipoint > ip address 165.128.100.2 255.255.255.0 > map-group ip-Pvc > atm pvc 121 0 121 aal5snap > ! > router eigrp 100 > network 165.128.0.0 > auto-summary > no eigrp log-neighbor-changes > ! > ip classless > ip http server > ! > ! > map-list ip-Pvc > ip 165.128.100.1 atm-vc 121 broadcast > ! > call rsvp-sync > ! > ! > mgcp profile default > ! > dial-peer cor custom > ! > ! > ! > ! > line con 0 > line aux 0 > line vty 0 4 > ! > ! > end > > THANKS! > > Eddie > > -Original Message- > From: Andre Riscalla [mailto:[EMAIL PROTECTED]] > Sent: Sunday, July 21, 2002 2:36 PM > To: Edward Sohn > Cc: [EMAIL PROTECTED] > Subject: Re: Lightstream PVC config problem... [7:49352] > > > > Edward, > > You are simply trying to define the same PVC mapping 2 times... > Basically you need to see the mapping of a PVC in the
