hi, all:
i'm in the middle of testing full lab 4 from INE and found something curious and i thought i'd ask. in this lab i have 3 ASBRs: R3 (ASN2000) and R5/XR1(ASN1000).
according to the instructions i'm supposed to have the following ebgp sessions:
R3<-->R5
R3<-->XR1
all loopbacks from both sides are supposed to be in the routing table for all devices.
now as afar as i know, the normal behavior for a bgp asbr is that whatever i learn on ibgp i send over to ebgp peers, no questions asked (and viceversa).
the thing is i'm seeing different behaviour in R5(IOS) and XR1(XR). R5 is doing this correctly:
R3#sib summ
[snip]
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
10.0.0.1 4 2000 84 81 17 0 0 01:04:56 2
10.0.35.5 4 1000 50 50 17 0 0 00:36:27 4
10.0.193.19 4 1000 14 16 17 0 0 00:09:23 3
R3#
while XR1 is not. XR1 does not redistribute iBGP automatically unless i exclicitly configure network statements (see above).XR1 (10.0.193.19) is only redistributing 3 loopback addresses instead of 4 because I did not add the network statement for the last loopback.
See config:
R5-IOS:
address-family ipv4
no synchronization
network 10.0.0.5 mask 255.255.255.255
neighbor 10.0.0.2 activate
neighbor 10.0.0.2 send-community both
XR1-IOSXR:
router bgp 1000
bgp router-id 10.0.0.19
address-family ipv4 unicast
network 10.0.0.5/32
network 10.0.0.19/32
network 10.0.0.20/32
allocate-label all
!
Again, AFAIN, bgp is supposed to do this automatically. is this a thing that's specific to XR? anyone?
While i'm at this, another weird thing is how the routing tables for bgp look in both devices. R5(IOS) marks igp-learned routes as rib-failure, but XR1(IOSXR) doesn't mark them as rib-failure. is this normal?
R5#sib
BGP table version is 19, local router ID is 10.0.0.5
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, x best-external
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 10.0.0.1/32 10.0.35.3 0 2000 i
r>i10.0.0.2/32 10.0.0.2 0 100 0 i
*> 10.0.0.3/32 10.0.35.3 0 0 2000 i
*> 10.0.0.4/32 10.0.35.3 0 2000 i
*> 10.0.0.5/32 0.0.0.0 0 32768 i
r>i10.0.0.19/32 10.0.0.19 0 100 0 i
r>i10.0.0.20/32 10.0.0.20 0 100 0 i
R5#
XR1 (IOSXR):
RP/0/0/CPU0:XR1#show bgp
Fri May 17 15:23:27.652 UTC
BGP router identifier 10.0.0.19, local AS number 1000
BGP generic scan interval 60 secs
BGP table state: Active
Table ID: 0xe0000000
BGP main routing table version 37
BGP scan interval 60 secs
Status codes: s suppressed, d damped, h history, * valid, > best
i - internal, r RIB-failure, S stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
* i10.0.0.1/32 10.0.0.5 0 100 0 2000 i
*> 10.0.193.3 0 2000 i
*>i10.0.0.2/32 10.0.0.2 0 100 0 i
* i10.0.0.3/32 10.0.0.5 0 100 0 2000 i
*> 10.0.193.3 0 0 2000 i
* i10.0.0.4/32 10.0.0.5 0 100 0 2000 i
*> 10.0.193.3 0 2000 i
*> 10.0.0.5/32 10.0.195.5 10 32768 i
* i 10.0.0.5 0 100 0 i
*> 10.0.0.19/32 0.0.0.0 0 32768 i
*> 10.0.0.20/32 10.19.20.20 10 32768 i
* i 10.0.0.20 0 100 0 i
Processed 7 prefixes, 12 paths
RP/0/0/CPU0:XR1#
thanks in advance!
c.