Quagga eBGP route advertisments are not propagated into iBGP session

Question

I am trying to do this: Load Sharing When Dual-Homed to One ISP Through Multiple Local Routers. The only difference from the example is that the ISP is sending a full BGP table instead of the default gateway. I have a problem that R101 won't advertise external routes to R102, which causes problem when R102's upstream peer disconnects, and R102 loses all routes.

My configuration:

R101 running configuration:

router bgp 6001
 no synchronization
 bgp router-id 1.1.2.253
 bgp log-neighbor-changes
 network 1.1.1.0
 network 1.1.2.0
 neighbor 2.1.1.249 remote-as 6000
 neighbor 2.1.1.249 soft-reconfiguration inbound
 neighbor 2.1.1.249 prefix-list 3 in
 neighbor 2.1.1.249 route-map R1-DC-MAP out
 neighbor 1.1.2.254 remote-as 6001
 neighbor 1.1.2.254 next-hop-self
 neighbor 1.1.2.254 soft-reconfiguration inbound
 maximum-paths 2
 no auto-summary
!
ip prefix-list 1 seq 5 permit 1.1.1.0/24
ip prefix-list 2 seq 5 permit 1.1.2.0/24
ip prefix-list 3 seq 5 deny 1.1.1.0/23
ip prefix-list 3 seq 10 permit any
!
route-map R1-DC-MAP permit 10
 match ip address prefix-list 1
 set as-path prepend 6001 6001 6001
!
route-map R1-DC-MAP permit 20
 match ip address prefix-list 2
!
route-map R1-DC-MAP deny 200

R102 running configuration:

router bgp 6001
 no synchronization
 bgp router-id 1.1.2.254
 bgp log-neighbor-changes
 network 1.1.1.0
 network 1.1.2.0
 neighbor 3.1.1.25 remote-as 6000
 neighbor 3.1.1.25 soft-reconfiguration inbound
 neighbor 3.1.1.25 prefix-list 3 in
 neighbor 3.1.1.25 route-map R2-SIX-MAP out
 neighbor 1.1.2.253 remote-as 6001
 neighbor 1.1.2.253 next-hop-self
 neighbor 1.1.2.253 soft-reconfiguration inbound
 maximum-paths 2
 no auto-summary
!
ip prefix-list 1 seq 5 permit 1.1.2.0/24
ip prefix-list 2 seq 5 permit 1.1.1.0/24
ip prefix-list 3 seq 5 deny 1.1.1.0/23
ip prefix-list 3 seq 10 permit any
!
route-map R2-SIX-MAP permit 10
 match ip address prefix-list 1
 set as-path prepend 6001 6001 6001
!
route-map R2-SIX-MAP permit 20
 match ip address prefix-list 2
!
route-map R2-SIX-MAP deny 30
 match ip address 1.1.1.0/23
!
route-map R2-SIX-MAP deny 200
!
ip forwarding
!
line vty
!
end

R101 interface list:

Interface vlan3 is up, line protocol detection is disabled
  inet 1.1.1.253/30 broadcast 1.1.1.255

Interface vlan4 is up, line protocol detection is disabled
  inet 2.1.1.253/29 broadcast 2.1.1.255

Interface vlan101 is up, line protocol detection is disabled
  inet 1.1.1.61/26 broadcast 1.1.1.63
  inet 1.1.1.1/32 broadcast 1.1.1.1

Interface vlan106 is up, line protocol detection is disabled
  inet 1.1.1.125/27 broadcast 1.1.1.127
  inet 1.1.1.97/32 broadcast 1.1.1.97

Interface vlan107 is up, line protocol detection is disabled
  inet 1.1.1.141/28 broadcast 1.1.1.143
  inet 1.1.1.129/28 broadcast 1.1.1.143 secondary

Interface vlan109 is up, line protocol detection is disabled
  inet 1.1.1.93/27 broadcast 1.1.1.95
  inet 1.1.1.65/32 broadcast 1.1.1.65

R102 interface configuration:

Interface vlan3 is up, line protocol detection is disabled
  inet 1.1.2.254/30 broadcast 1.1.2.255

Interface vlan4 is up, line protocol detection is disabled
  inet 3.1.1.29/29 broadcast 3.1.1.31

Interface vlan101 is up, line protocol detection is disabled
  inet 1.1.2.62/26 broadcast 1.1.2.63
  inet 1.1.2.1/32 broadcast 1.1.2.1

Interface vlan106 is up, line protocol detection is disabled
  inet 1.1.2.126/27 broadcast 1.1.2.127
  inet 1.1.2.97/32 broadcast 1.1.2.97

Interface vlan107 is up, line protocol detection is disabled
  inet 1.1.2.142/28 broadcast 1.1.2.143
  inet 1.1.2.129/28 broadcast 1.1.2.143 secondary

Interface vlan109 is up, line protocol detection is disabled
  inet 1.1.2.94/27 broadcast 1.1.2.95
  inet 1.1.2.65/32 broadcast 1.1.2.65

Advertisements are not working at all on R101, but I can see advertisements coming from R102. Communication with the upstream ISP BGP peers works as expected, and I am obtaining full BGP from them.

R101 advertisements:

BGP table version is 0, local router ID is 1.1.2.253
Status codes: s suppressed, d damped, h history, * valid, > best, = multipath,
              i internal, r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path

R101 received-routes:

BGP table version is 0, local router ID is 1.1.2.253
Status codes: s suppressed, d damped, h history, * valid, > best, = multipath,
              i internal, r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.0     1.1.2.254           0    100      0 i
*> 1.1.2.0     1.1.2.254           0    100      0 i

Total number of prefixes 2

Does anyone have any ideas what may be wrong?

Answer 1

The network statements in your BGP router configuration:

network 1.1.1.0
network 1.1.2.0

do not match the actual network addresses, which range from /26 to /32. BGP will not advertise networks which do not exactly match what is in the routing table unless you you use the aggregate-address command. Network statements in BGP will not make up routes that don't already exist.

Answer 2

I guess that the problem is with your supporting routes for 1.1.1.0/24 and 1.1.2.0/24.

To announce a prefix, you need a supporting route in RIB. So, you should have 1.1.1.0/24 and 1.1.2.0/24 in RIB to be able to announce them.

I assume you can't change your SVI's IP addressing, thus maybe you can enter two /24 routes towards the south of your network, or to Null0. Then the BGP network command will take effect.