Here is the exact Scenario:
(considering 1.1.1.0/24 is our own RIPE assigned public space...)
RTR-A: 10MB Fast Ether to ISP-A
router bgp 42460
no synchronization
bgp log-neighbor-changes
network 1.1.1.0 mask 255.255.255.0
network 10.10.10.4 mask 255.255.255.224
neighbor 213.10.96.48 remote-as 21530
neighbor 213.10.96.48 ebgp-multihop 255
neighbor 213.10.96.48 remove-private-as
neighbor 213.10.96.48 soft-reconfiguration inbound
neighbor 213.10.96.48 distribute-list 15 out
neighbor 213.10.96.49 remote-as 21530
neighbor 213.10.96.49 ebgp-multihop 255
neighbor 213.10.96.49 remove-private-as
neighbor 213.10.96.49 soft-reconfiguration inbound
neighbor 213.10.96.49 distribute-list 15 out
no auto-summary
!
Fast Ether 0/1
descruption : LAN
ip address 1.1.1.2 255.255.255.0
standby 10 1.1.1.1
standby 10 preempt delay minimum 60
standby 10 priority 155
standby 10 track fast 0/0
!
distribute-list 15 : has ACL permits 1.1.1.0/24 and other /28 range to ISP-A
-----------------------------------
RTR B to ISP-B : 2MB via Serila0/0
router bgp 42460
no synchronizartion
bgp log-neighbor-changes
network 1.1.1.0 mask 255.255.255.0
neighbor 229.23.50.157 remote-as 6466
neighbor 229.23.50.157 next-hop-self
neighbor 229.23.50.157 soft-reconfiguration inbound
neighbor 229.23.50.157 route-map set-as-path out
!
ip prefix-list ISP-B seq 10 permit 1.1.1.0/24
ip prefix-list ISP-B seq 20 deny 0.0.0.0/0 le 32
!
route-map set-as-path permit 10
match ip address prefix-list ISP-B
set as-path prepend 42460 42460 42460 42460 42460
!
inter fast 0/1
description: LAN
Fast Ether 0/1
descruption : LAN
ip address 1.1.1.3 255.255.255.0
standby 10 1.1.1.1
standby 10 preempt
standby 10 priority 150
______________________________________
When I ran the test with some down time, it was observed that
1. when ISP-A link fails, it took 4-5mins for the internet to failover to ISP-B.
2. Also, when ISP-A is active, the traceroute from my PC to the public IP at this location, taking ISP-B path.
So after careful reviews, we observerved..
a) synchronization diff in both our local rtrs b) there may be IBGP required between both rtrs c) AS Path Prepend is not 100% perfect solution for primary/back up solution.
We might go with Communities or Conditional advt.
As my ISP-B does not support communities, Iam thinking of Conditional advt.
So iam looking for confg example with 2 rts, 2dual ISPs.
Thank you
MS
Also, as rtrs residing outside of firewall and not communicatiing with any internal IGP (in LAN), do I still need IBGP between these routers..? or the configs I mentioned are sufficient..?
Please suggest.
Thank you in advance
MS
