[c-nsp] Changing ve id doesn't withdraw old prefixes
Jason Lixfeld
jason at lixfeld.ca
Thu Jun 20 16:09:31 EDT 2013
I've just set up BGP signalled VPLS w/auto discovery between two 15.3(2)S1 ME3600 boxes and I'm seeing something a little odd. I'll admit I'm very new to the BGP VPLS stuff, but I'm sure this is not right in the head...
Topology:
+--------- ASR9K RR 1 --------+
trs01.002 trs02.002
+--------- ASR9K RR 2 --------+
I found a thread on stackexchange.com (http://networkengineering.stackexchange.com/questions/1722/bgp-signalled-mpls-issues) about a BGP signalling bug, but I'm not sure if this is the same issue or not.
--
I have a config like so on one PE:
! trs02.002.77MowatAv01.YYZ Config
!
interface Loopback 0
ip address 72.15.50.129 255.255.255.255
!
l2vpn vfi context test
vpn id 69
autodiscovery bgp signaling bgp
ve id 10129
rd 21949:2194900069
route-target export 21949:2194900069
route-target import 21949:2194900069
!
!
!
interface Vlan69
vrf forwarding test
ip address 10.0.0.2 255.255.255.0
member vfi test
!
>From another auto-discovered PE, I see (what I believe to be) correct BGP telemetry:
trs01.002.77MowatAv01.YYZ#show bgp l2vpn vpls rd 21949:2194900069
BGP table version is 214, local router ID is 72.15.50.33
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 21949:2194900069
*> 21949:2194900069:VEID-10033:Blk-10030/136
0.0.0.0 32768 ?
*> 21949:2194900069:VEID-10033:Blk-10120/136
0.0.0.0 32768 ?
* i 21949:2194900069:VEID-10129:Blk-10030/136
72.15.50.129 0 100 0 ?
*>i 72.15.50.129 0 100 0 ?
*>i 21949:2194900069:VEID-10129:Blk-10120/136
72.15.50.129 0 100 0 ?
* i 72.15.50.129 0 100 0 ?
trs01.002.77MowatAv01.YYZ#
Now then, if I adjust the ve id on trs02.002, the same auto-discovered PE (trs01.002) still sees the old BGP telemetry. I'd expect this to get withdrawn as soon as the ve id changes:
! trs02.002.77MowatAv01.YYZ Config
!
l2vpn vfi context test
vpn id 69
autodiscovery bgp signaling bgp
ve id 10001
rd 21949:2194900069
route-target export 21949:2194900069
route-target import 21949:2194900069
!
!
!
trs01.002.77MowatAv01.YYZ#show bgp l2vpn vpls rd 21949:2194900069
BGP table version is 219, local router ID is 72.15.50.33
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 21949:2194900069
* i 21949:2194900069:VEID-10001:Blk-10000/136
72.15.50.129 0 100 0 ?
*>i 72.15.50.129 0 100 0 ?
* i 21949:2194900069:VEID-10001:Blk-10030/136
72.15.50.129 0 100 0 ?
*>i 72.15.50.129 0 100 0 ?
*> 21949:2194900069:VEID-10033:Blk-10000/136
0.0.0.0 32768 ?
*> 21949:2194900069:VEID-10033:Blk-10030/136
0.0.0.0 32768 ?
*> 21949:2194900069:VEID-10033:Blk-10120/136
0.0.0.0 32768 ?
* i 21949:2194900069:VEID-10129:Blk-10030/136
72.15.50.129 0 100 0 ?
*>i 72.15.50.129 0 100 0 ?
*>i 21949:2194900069:VEID-10129:Blk-10120/136
72.15.50.129 0 100 0 ?
* i 72.15.50.129 0 100 0 ?
trs01.002.77MowatAv01.YYZ#
If I restore the ve id on trs02.002 to it's original value of 10129, the modified ve id also stays persistent, but the VFI stops passing traffic all together at this point:
trs01.002.77MowatAv01.YYZ#show bgp l2vpn vpls rd 21949:2194900069
BGP table version is 219, local router ID is 72.15.50.33
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 21949:2194900069
* i 21949:2194900069:VEID-10001:Blk-10000/136
72.15.50.129 0 100 0 ?
*>i 72.15.50.129 0 100 0 ?
* i 21949:2194900069:VEID-10001:Blk-10030/136
72.15.50.129 0 100 0 ?
*>i 72.15.50.129 0 100 0 ?
*> 21949:2194900069:VEID-10033:Blk-10000/136
0.0.0.0 32768 ?
*> 21949:2194900069:VEID-10033:Blk-10030/136
0.0.0.0 32768 ?
*> 21949:2194900069:VEID-10033:Blk-10120/136
0.0.0.0 32768 ?
* i 21949:2194900069:VEID-10129:Blk-10030/136
72.15.50.129 0 100 0 ?
*>i 72.15.50.129 0 100 0 ?
*>i 21949:2194900069:VEID-10129:Blk-10120/136
72.15.50.129 0 100 0 ?
* i 72.15.50.129 0 100 0 ?
trs01.002.77MowatAv01.YYZ#ping vrf test 10.0.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.2, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
trs01.002.77MowatAv01.YYZ#
If I delete the vfi and SVI on both ME3600s, BGP still doesn't seem to want to flush this stuff out...
trs02.002.77MowatAv01.YYZ#conf t
Enter configuration commands, one per line. End with CNTL/Z.
trs02.002.77MowatAv0(config)#no int vlan 69
trs02.002.77MowatAv0(config)#no l2vpn vfi context test
trs02.002.77MowatAv0(config)#^Z
trs02.002.77MowatAv01.YYZ#sh run | i 21949:2194900069
trs02.002.77MowatAv01.YYZ#
trs01.002.77MowatAv01.YYZ#show bgp l2vpn vpls rd 21949:2194900069
BGP table version is 226, local router ID is 72.15.50.33
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 21949:2194900069
* i 21949:2194900069:VEID-10001:Blk-10000/136
72.15.50.129 0 100 0 ?
*>i 72.15.50.129 0 100 0 ?
* i 21949:2194900069:VEID-10001:Blk-10030/136
72.15.50.129 0 100 0 ?
*>i 72.15.50.129 0 100 0 ?
trs01.002.77MowatAv01.YYZ#
The RRs don't see anything:
RP/0/RSP0/CPU0:bfr01.77MowatAv01.YYZ#show bgp l2vpn vpls rd 21949:2194900069
Thu Jun 20 16:02:51.687 EDT
RP/0/RSP0/CPU0:bfr01.77MowatAv01.YYZ#
RP/0/RSP0/CPU0:bfr01.151FrontStW01.YYZ#show bgp l2vpn vpls rd 21949:2194900069
Thu Jun 20 16:03:42.031 EDT
RP/0/RSP0/CPU0:bfr01.151FrontStW01.YYZ#
The only workaround I've been able to come up with is to hard clear the BGP session on the ME3600s facing the RRs. This is easily replicated on both ME3600s.
dafuq?
Any ideas?
Thanks in advance.
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