If I understand you correctly, I don't think that HRSP is what you need. HRSP is good if upstream serial interfaces go down, or something like that, or for router redundancy, but in your situation I would suggest letting your IGP determine which upstream is active, based on who is still advertising the default BGP prefix. If you are using OSPF, you could use #default-information originate. If the BGP default prefix is the only default route on your edge routers, the OSPF default will disappear if the BGP default disappears. If you don't use OSPF, just redistribute the BGP default into your IGP.
I am assuming that when your ISP goes "down", they stop sending the BGP default. This will allow 1 of 2 things to happen. If your downstream devices are IGP routers, they will already know the best to the good BGP upstream. If they are hosts with static default routes, then their default gateway could always relay the packet, or suggest an ICMP redirect to the host. Let me know if this helps! Jay Greenberg On Fri, 2002-07-26 at 14:50, sam sneed wrote: > I have a pair of 2621's and 2 reduandant ethernet handoffs to my ISP. 1 is a > primary and the other is a backup which should only be used if the primary > fails. On my side i am running HSRP for fault tolerance RA is configured > asprimary in my HSRP group. I will be doing BGP peering with my provider. I > only want to receive default routes. I almost have the full config but am > confused on 1point. If ISPA goes loses connectivity a couple hops upstream > HSRP will not fail over becasue my link is physically up so all my internal > hosts will still go through RA eth0. How do I get them to go through RA eth0 > then to RB eth0 and then eventually through the backup ISP link, ISP B. Keep > in mind its the same ISP, AS#, just a different connection. Its a huge ISP. > Is there some kind of peering needed between RA and RB, maybe some special > commands? > Am I at least on the right track? > My configs are posted below. > > If the ascii art gets confusing I have posted good a diagram as a gif at : > > http://sbnet.freeservers.com/bgp.gif > > virtual router > All routers use AS100 > ____________________ > __________________ > 172.16.20.0 ---> | 172.16.10.2--->RA | > 192.168.133.1------->|ISPA 192.168.133.2 | ----->internet > 172.16.30.0 --> | ------------------------| (RA eth1) > |__________________| > 172..16.10.0 ---> | 172.16.10.1-->HSRP | > | ----------------------- | > | 172.16.10.3---->RB | > _________________ > |___________________| > 192.168.100.1--------->|ISPB 192.168.100.2|------>internet > > (RB eth1) |________________| > > > Router A > ----------------------------------- > ------------------------------------ > interface FastEthernet0/0 > ip address 172.16.10.2 255.255.255.0 > standby priority 105 > standby 244 ip 172.16.10.1 > standby 244 preempt > standby 244 track FastEthernet0/1 > ! > interface FastEthernet0/1 > ip address ip address 192.168.100.1 255.255.255.252 > > > router bgp 100 > no synchronization > network 172.16.10.0 > network 172.16.20.0 > network 172.16.30.0 > neighbor 192.168.133.2 remote-as 100 > neighbor 192.168.133.2 prefix-list ABC in > neighbor 172.16.10.3 remote-as 100 > no auto-summary > ! > > ip prefix-list ABC seq 5 permit 0.0.0.0/0 > > end > > > > > Router B > ------------------------------------ > interface FastEthernet0/0 > ip address 172.16.10.3 255.255.255.0 > standby priority 100 > standby 244 ip 172.16.10.1 > standby 244 preempt > standby 244 track FastEthernet0/1 > ! > interface FastEthernet0/1 > ip address ip address 192.168.100.1 255.255.255.252 > > router bgp 100 > no synchronization > network 172.16.10.0 > network 172.16.20.0 > network 172.16.30.0 > neighbor 192.168.100.2 remote-as 100 > neighbor 192.168.100.2 prefix-list ABC in > neighbor 172.16.10.2 remote-as 100 > no auto-summary > ! > ip prefix-list ABC seq 5 permit 0.0.0.0/0 > > end Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=49820&t=49807 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
