BGP Graceful Restart

Hi,

I was wondering if anyone can explain why I see this output from show BGP neighbor:

Address family IPv4 Unicast: advertised and received
Graceful Restart Capability: advertised and received
  Remote Restart timer is 120 seconds
  Address families advertised by peer:
    IPv4 Unicast (was preserved
  Address families advertised by peer before restart:
    VPNv4 Unicast

Apart from the syntax which looks strange (seems like "was preserved" was cut short for some reason. No closing parentheses), I don't understand why I see "Address families advertised by peer before restart: VPNv4 Unicast".

This is a MPLS network, but this particular peering is a ipv4 peering in a VRF.

Does this look strange or is this normal behavior?

Additional information and configuration:

switch#sho bgp vpnv4 unicast vrf CLIENT neighbors 10.1.0.1
BGP neighbor is 10.1.0.1, vrf CLIENT, remote AS 64799, local AS 64601 no-prepend replace-as, external link
BGP version 4, remote router ID 10.127.0.1
BGP state = Established, up for 9w6d
Last read 00:00:13, last write 00:00:21, hold time is 90, keepalive interval is 30 seconds
Neighbor sessions:
1 active, is not multisession capable (disabled)
Neighbor capabilities:
Route refresh: advertised and received(new)
Four-octets ASN Capability: advertised
Address family IPv4 Unicast: advertised and received
Graceful Restart Capability: advertised and received
Remote Restart timer is 120 seconds
Address families advertised by peer:
IPv4 Unicast (was preserved
Address families advertised by peer before restart:
VPNv4 Unicast
Enhanced Refresh Capability: advertised
Multisession Capability:
Stateful switchover support enabled: NO for session 1
Message statistics:
InQ depth is 0
OutQ depth is 0

                     Sent       Rcvd
Opens:                  1          1
Notifications:          0          0
Updates:               11          2
Keepalives:        218588     230420
Route Refresh:          0          0
Total:             218600     230423

Do log neighbor state changes (via global configuration)
Default minimum time between advertisement runs is 0 seconds

For address family: VPNv4 Unicast
Translates address family IPv4 Unicast for VRF CLIENT
Session: 10.1.0.1
BGP table version 627, neighbor version 627/0
Output queue size : 0
Index 24, Advertise bit 0
24 update-group member
Inbound soft reconfiguration allowed
Community attribute sent to this neighbor
Extended-community attribute sent to this neighbor
Outbound path policy configured
Route map for outgoing advertisements is 64600->64799
Slow-peer detection is disabled
Slow-peer split-update-group dynamic is disabled
Sent Rcvd
Prefix activity: ---- ----
Prefixes Current: 78 1 (Consumes 256 bytes)
Prefixes Total: 81 2
Implicit Withdraw: 1 1
Explicit Withdraw: 2 0
Used as bestpath: n/a 1
Used as multipath: n/a 0
Used as secondary: n/a 0
Saved (soft-reconfig): n/a 1 (Consumes 128 bytes)

                               Outbound    Inbound

Local Policy Denied Prefixes: -------- -------
Other Policies: 2 n/a
Total: 2 0
Number of NLRIs in the update sent: max 39, min 0
Last detected as dynamic slow peer: never
Dynamic slow peer recovered: never
Refresh Epoch: 1
Last Sent Refresh Start-of-rib: never
Last Sent Refresh End-of-rib: never
Last Received Refresh Start-of-rib: never
Last Received Refresh End-of-rib: never
Sent Rcvd
Refresh activity: ---- ----
Refresh Start-of-RIB 0 0
Refresh End-of-RIB 0 0

Address tracking is enabled, the RIB does have a route to 10.1.0.1
Route to peer address reachability Up: 1; Down: 0
Last notification 13w6d
Connections established 5; dropped 4
Last reset 9w6d, due to NSF peer closed the session of session 1
External BGP neighbor configured for connected checks (single-hop no-disable-connected-check)
Interface associated: Vlan3099 (peering address in same link)
Transport(tcp) path-mtu-discovery is enabled
Graceful-Restart is enabled, restart-time 120 seconds, stalepath-time 360 seconds
SSO is disabled
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Connection is ECN Disabled, Mininum incoming TTL 0, Outgoing TTL 1
Local host: 10.1.0.12, Local port: 179
Foreign host: 10.1.0.1, Foreign port: 45055
Connection tableid (VRF): 2
Maximum output segment queue size: 50

Enqueued packets for retransmit: 0, input: 0 mis-ordered: 0 (0 bytes)

Event Timers (current time is 0x1F7391982):
Timer Starts Wakeups Next
Retrans 220258 1664 0x0
TimeWait 0 0 0x0
AckHold 230424 225662 0x0
SendWnd 0 0 0x0
KeepAlive 0 0 0x0
GiveUp 0 0 0x0
PmtuAger 0 0 0x0
DeadWait 0 0 0x0
Linger 0 0 0x0
ProcessQ 0 0 0x0

iss: 442083812 snduna: 446238040 sndnxt: 446238040
irs: 1672834350 rcvnxt: 1677212464

sndwnd: 2920 scale: 0 maxrcvwnd: 16384
rcvwnd: 15567 scale: 0 delrcvwnd: 817

SRTT: 1000 ms, RTTO: 1003 ms, RTV: 3 ms, KRTT: 0 ms
minRTT: 0 ms, maxRTT: 1003 ms, ACK hold: 200 ms
uptime: -1 ms, Sent idletime: 10295 ms, Receive idletime: 10293 ms
Status Flags: passive open, gen tcbs
Option Flags: VRF id set, nagle, path mtu capable, md5, Retrans timeout
IP Precedence value : 6

Datagrams (max data segment is 1460 bytes):
Rcvd: 448966 (out of order: 0), with data: 230424, total data bytes: 4378113
Sent: 447251 (retransmit: 1664, fastretransmit: 0, partialack: 0, Second Congestion: 0), with data: 218594, total data bytes: 4154227

Packets received in fast path: 0, fast processed: 0, slow path: 0
fast lock acquisition failures: 0, slow path: 0
TCP Semaphore 0xFFB54495F8 FREE

router bgp 64600
bgp router-id vrf auto-assign
bgp log-neighbor-changes
bgp graceful-restart
no bgp default ipv4-unicast
neighbor 10.1.1.33 remote-as 64600
neighbor 10.1.1.33 update-source Loopback50
neighbor 10.1.1.34 remote-as 64600
neighbor 10.1.1.34 update-source Loopback50
neighbor 10.1.1.35 remote-as 64600
neighbor 10.1.1.35 update-source Loopback50
!
address-family vpnv4
neighbor 10.1.1.33 activate
neighbor 10.1.1.33 send-community both
neighbor 10.1.1.33 route-reflector-client
neighbor 10.1.1.34 activate
neighbor 10.1.1.34 send-community both
neighbor 10.1.1.34 route-reflector-client
neighbor 10.1.1.35 activate
neighbor 10.1.1.35 send-community both
neighbor 10.1.1.35 route-reflector-client
exit-address-family
!
address-family ipv4 vrf CLIENT
neighbor 10.1.0.1 remote-as 64799
neighbor 10.1.0.1 local-as 64601 no-prepend replace-as
neighbor 10.1.0.1 activate
neighbor 10.1.0.1 send-community both
maximum-paths ibgp 4
default-information originate
exit-address-family

Sign In or Register to comment.