BGP 4+ states

Like for BGP 4, the BGP 4+ states reflect the state of the BGP 4+ session. A valid BGP 4+ session must be in ESTABLISHED state. Its state can be verified with the following command:

router{}show routing ipv6 bgp summary
BGP router identifier 10.1.1.1, local ASN 65510
2 BGP AS-PATH entries
0 BGP community entries

Neighbor   V     AS  MsgRcvd MsgSent TblVer InQ OutQ Up/Down  State/PfxRcd
3ffe:1::2  4  65520       26      19      0   0    0 00:14:11       5
Total number of neighbors 1

The BGP states are: IDLE, ACTIVE, CONNECT, OPENSENT, OPENCONFIRM, and ESTABLISHED.

IDLE
The router will not accept connections from the peer. This state is entered briefly after a connection has timed out.
ACTIVE
The router is listening for connection requests from the peers.
CONNECT
The router has sent out an active TCP connection request to the peer.
OPENSENT and OPENCONFIRM
The two peers are exchanging packets to establish their BGP session. If the exchanges are successful, the peers will enter the ESTABLISHED state.

The peers must continue to exchange periodic KEEPALIVE packets to remain in the ESTABLISHED state, unless the negotiated hold time is 0.

show routing ipv6 bgp

  • Display the IPv6 RIB of the BGP 4+ protocol.

    router{}show routing ipv6 bgp
    BGP table version is 0, local router ID is 10.1.1.2
    Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
    Origin codes: i -IGP, e - EGP, ? - incomplete
    
    Network Next Hop Metric LocPrf Weight Path
    *> 2001:1::/48 3ffe:2::2 0 0 65530 i
    *> 2001:1:1::/48 3ffe:2::2 0 0 65530 i
    *> 2001:1:2::/48 :: 0 32768 i
    *> 2001:1:3::/48 :: 0 32768 i
    
    * 3ffe:1::/64 3ffe:1::1 0 0 65510 i
    *> :: 0 32768 i
    
    Total number of prefixes 5
    

The various fields that are displayed, are described in the following list:

local router ID
This id is used to identify the router, it must be manually configured in the format of IPv4 address, using the command bgp router-id.
Status codes:
s
means the entry is suppressed
d
means the prefix was dampened (in case dampening is enabled)
*
means the entry is valid
>
in case there are multiple entries for this prefix > indicates the best one
i
means that this entry was learned by interior BGP (in the same AS)
e
means that this entry was learned by exterior BGP (different AS)
?
means that this entry was learned through redistribution
Origin codes:
i
means that the origin of this entry is interior BGP (in the same AS)
e
means that the origin of this entry is exterior BGP (different AS)
?
means that the origin of this entry is redistribution
Network
This is the prefix entry in the BGP 4+ RIB
Next Hop
This is the next-hop attribute advertised by BGP 4+ in case the next-hop is :: it means that this prefix is originated locally.
Metric
This the Multi-exit Descriminator value (see the BGP options)
LocPrf
This is the local preference value (see the BGP options) by default it is set to 100
Weight
This the weight associated to the prefix (See BGP options) by default the received routes is set to 0 while the weight of local routes is 32768