show ip bgp neighbors [address] [received-routes | routes | advertised-routes | {pathsregular-expression} | dampened-routes]

http://www.cisco.com/en/US/docs/ios/12_0/np1/command/reference/1rbgp.html#wp1022538

Examples

The following is sample output from the show ip bgp neighbors command:

Router# show ip bgp neighbors 172.16.232.178

BGP neighbor is 172.16.232.178,  remote AS 10, external link

Index 1, Offset 0, Mask 0x2

Inbound soft reconfiguration allowed

BGP version 4, remote router ID 172.16.232.178

BGP state = Established, table version = 27, up for 00:06:12

Last read 00:00:12, hold time is 180, keepalive interval is 60 seconds

Minimum time between advertisement runs is 30 seconds

Received 19 messages, 0 notifications, 0 in queue

Sent 17 messages, 0 notifications, 0 in queue

Inbound path policy configured

Route map for incoming advertisements is testing

Connections established 2; dropped 1

Connection state is ESTAB, I/O status: 1, unread input bytes: 0

Local host: 172.16.232.181, Local port: 11002

Foreign host: 172.16.232.178, Foreign port: 179

Enqueued packets for retransmit: 0, input: 0, saved: 0

Event Timers (current time is 0x530C294):

Timer          Starts    Wakeups            Next

Retrans            12          0             0x0

TimeWait            0          0             0x0

AckHold            12         10             0x0

SendWnd             0          0             0x0

KeepAlive           0          0             0x0

GiveUp              0          0             0x0

PmtuAger            0          0             0x0

iss:  133981889  snduna:  133982166  sndnxt:  133982166     sndwnd:  16108

irs: 3317025518  rcvnxt: 3317025810  rcvwnd:      16093  delrcvwnd:    291

SRTT: 441 ms, RTTO: 2784 ms, RTV: 951 ms, KRTT: 0 ms

minRTT: 0 ms, maxRTT: 300 ms, ACK hold: 300 ms

Flags: higher precedence, nagle

Datagrams (max data segment is 1460 bytes):

Rcvd: 15 (out of order: 0), with data: 12, total data bytes: 291

Sent: 23 (retransmit: 0), with data: 11, total data bytes: 276

Table 46 describes the fields shown in the display.

Table 46 show ip bgp neighbors Field Descriptions 

Field	Description
BGP neighbor	IP address of the BGP neighbor and its autonomous system number. If the neighbor is in the same autonomous system as the router, then the link between them is internal; otherwise, it is considered external.
BGP version	BGP version being used to communicate with the remote router; the neighbor's router ID (an IP address) is also specified.
BGP state	Internal state of this BGP connection.
table version	Indicates that the neighbor has been updated with this version of the primary BGP routing table.
up for	Amount of time that the underlying TCP connection has been in existence.
Last read	Time that BGP last read a message from this neighbor.
hold time	Maximum amount of time that can elapse between messages from the peer.
keepalive interval	Time period between sending keepalive packets, which help ensure that the TCP connection is up.
Received	Number of total BGP messages received from this peer, including keepalives.
notifications	Number of error messages received from the peer.
Sent	Total number of BGP messages that have been sent to this peer, including keepalives.
notifications	Number of error messages the router has sent to this peer.
Connections established	Number of times the router has established a TCP connection and the two peers have agreed speak BGP with each other.
dropped	Number of times that a good connection has failed or been taken down.
Connection state	State of BGP peer.
unread input bytes	Number of bytes of packets still to be processed.
Local host, Local port	Peering address of local router, plus port.
Foreign host, Foreign port	Neighbor's peering address.
Event Timers	Table displays the number of starts and wakeups for each timer.
iss	Initial send sequence number.
snduna	Last send sequence number the local host sent but has not received an acknowledgment for.
sndnxt	Sequence number the local host will send next.
sndwnd	TCP window size of the remote host.
irs	Initial receive sequence number.
rcvnxt	Last receive sequence number the local host has acknowledged.
rcvwnd	Local host's TCP window size.
delrecvwnd	Delayed receive window—data the local host has read from the connection, but has not yet subtracted from the receive window the host has advertised to the remote host. The value in this field gradually increases until it is larger than a full-sized packet, at which point it is applied to the rcvwnd field.
SRTT	A calculated smoothed round-trip timeout.
RTTO	Round-trip timeout.
RTV	Variance of the round-trip time.
KRTT	New round-trip timeout (using the Karn algorithm). This field separately tracks the round-trip time of packets that have been retransmitted.
minRTT	Smallest recorded round-trip timeout (hard wire value used for calculation).
maxRTT	Largest recorded round-trip timeout.
ACK hold	Time the local host will delay an acknowledgment in order to piggyback data on it.
Flags	IP precedence of the BGP packets.
Datagrams: Rcvd	Number of update packets received from neighbor.
with data	Number of update packets received with data.
total data bytes	Total bytes of data.
Sent	Number of update packets sent.
with data	Number of update packets with data sent.
total data bytes	Total number of data bytes.