Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) - Manual (Page 39)

Multi-Service IronWare Routing Configuration Guide 11
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BGP4 Restart
BGP4 Peer notification during a management
module switchover
The BGP4 Peer notification process restores BGP4 adjacency quickly and allows packet forwarding
between the newly active management module and the BGP4 peers. The handling of TCP packets
with an MD5 digest prevents the silent dropping of TCP packets without triggering a RESET packet.
The BGP4 peer notification process operates effectively when implemented for the following
processes that involve the intentional switching of the active status from one management module
to another:
• System Reload – When a device undergoes the reload process, both management modules
and all interface modules are rebooted. All BGP4 sessions are terminated BEFORE the system
triggers the hardware reset.
• Switchover Requested by User – Switching over to a standby management module can be
triggered by the switchover, reset, reload, and hitless-reload commands. When these
commands are executed, the active management module resets the BGP4/TCP sessions with
BGP4 neighbors before transferring control to the standby management module.
NOTE
Graceful-restart-enabled BGP4 sessions are not reset. The BGP4 graceful-restart protocol allows a
BGP4 session to reconnect gracefully without going through the normal process.
Figure 2 describes the procedure used between the management modules in a device and a BGP4
neighbor device.
FIGURE 2 Management module switchover behavior for BGP4 peer notification