Capturing Pdus - Dell S4820T Configuration Manual

Capabilities advertised to neighbor for IPv4 Unicast :
MULTIPROTO_EXT(1)
ROUTE_REFRESH(2)
CISCO_ROUTE_REFRESH(128)
For address family: IPv4 Unicast
BGP table version 1395, neighbor version 1394
Prefixes accepted 1 (consume 4 bytes), 0 withdrawn by peer
Prefixes advertised 0, rejected 0, 0 withdrawn from peer
Connections established 3; dropped 2
Last reset 00:00:12, due to Missing well known attribute
Notification History
'UPDATE error/Missing well-known attr' Sent : 1 Recv: 0
'Connection Reset' Sent : 1 Recv: 0
Last notification (len 21) sent 00:26:02 ago
ffffffff ffffffff ffffffff ffffffff 00160303 03010000
Last notification (len 21) received 00:26:20 ago
ffffffff ffffffff ffffffff ffffffff 00150306 00000000
Last PDU (len 41) received 00:26:02 ago that caused notification to be issued
ffffffff ffffffff ffffffff ffffffff 00290200 00000e01 02040201 00024003
04141414 0218c0a8
01000000
Local host: 1.1.1.1, Local port: 179
Foreign host: 1.1.1.2, Foreign port: 41758

Capturing PDUs

To capture incoming and outgoing PDUs on a per-peer basis, use the capture bgp-pdu neighbor
direction command. To disable capturing, use the no capture bgp-pdu neighbor direction
command.
The buffer size supports a maximum value between 40 MB (the default) and 100 MB. The capture buffers
are cyclic and reaching the limit prompts the system to overwrite the oldest PDUs when new ones are
received for a given neighbor or direction. Setting the buffer size to a value lower than the current
maximum, might cause captured PDUs to be freed to set the new limit.
NOTE: Memory on RP1 is not pre-allocated and is allocated only when a PDU needs to be captured.
The buffers storing the PDU free memory when:
• BGP is disabled.
• A neighbor is unconfigured.
• The clear ip bgp command is issued.
• New PDU are captured and there is no more space to store them.
• The max buffer size is reduced. (This may cause PDUs to be cleared depending on the buffer space
consumed and the new limit.)
Examples of the show capture bgp-pdu neighbor Command
To change the maximum buffer size, use the capture bgp-pdu max-buffer-size command. To
view the captured PDUs, use the show capture bgp-pdu neighbor command.
Dell#show capture bgp-pdu neighbor 20.20.20.2
Incoming packet capture enabled for BGP neighbor 20.20.20.2
Available buffer size 40958758, 26 packet(s) captured using 680 bytes
PDU[1] : len 101, captured 00:34:51 ago
ffffffff ffffffff ffffffff ffffffff 00650100 00000013 00000000 00000000
Border Gateway Protocol IPv4 (BGPv4)
255