Cisco Catalyst 3750-E Software Configuration Manual page 1030

Configuring BGP
establish a TCP session. A soft reset allows the dynamic exchange of route refresh requests and routing
information between BGP routers and the subsequent re-advertisement of the respective outbound
routing table.
•
•
A soft inbound reset causes the new inbound policy to take effect. A soft outbound reset causes the new
local outbound policy to take effect without resetting the BGP session. As a new set of updates is sent
during outbound policy reset, a new inbound policy can also take effect.
Table 40-10
Table 40-10 Advantages and Disadvantages of Hard and Soft Resets
Type of Reset
Hard reset
Outbound soft reset
Dynamic inbound soft reset Does not clear the BGP session and cache
Beginning in privileged EXEC mode, follow these steps to learn if a BGP peer supports the route refresh
capability and to reset the BGP session:
Command
Step 1 show ip bgp neighbors
Step 2 clear ip bgp {* | address |
peer-group-name}
Step 3
clear ip bgp {* | address |
peer-group-name} soft out
Step 4 show ip bgp
show ip bgp neighbors
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
40-52
When soft reset generates inbound updates from a neighbor, it is called dynamic inbound soft reset.
When soft reset sends a set of updates to a neighbor, it is called outbound soft reset.
lists the advantages and disadvantages hard reset and soft reset.
Advantages
No memory overhead
No configuration, no storing of routing table
updates
Does not require storing of routing table updates
and has no memory overhead
Purpose
Display whether a neighbor supports the route refresh capability. When supported,
this message appears for the router:
Received route refresh capability from peer.
Reset the routing table on the specified connection.
Enter an asterisk (*) to specify that all connections be reset.
•
Enter an IP address to specify the connection to be reset.
•
Enter a peer group name to reset the peer group.
•
(Optional) Perform an outbound soft reset to reset the inbound routing table on the
specified connection. Use this command if route refresh is supported.
• Enter an asterisk (*) to specify that all connections be reset.
• Enter an IP address to specify the connection to be reset.
• Enter a peer group name to reset the peer group.
Verify the reset by checking information about the routing table and about BGP
neighbors.
Chapter 40 Configuring IP Unicast Routing
Disadvantages
The prefixes in the BGP, IP, and FIB tables
provided by the neighbor are lost. Not
recommended.
Does not reset inbound routing table updates.
Both BGP routers must support the route
refresh capability (in Cisco IOS Release 12.1
and later).
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