Brocade Communications Systems ICX 7250 series, Configuration Manual

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Parameter changes that take effect after disabling and re-enabling
redistribution
The following parameter change takes effect only after you disable and then re-enable redistribution:
• Change the default MED (metric).
Memory considerations
BGP4 can handle a very large number of routes and therefore requires a lot of memory. For example, in a typical configuration with a
single BGP4 neighbor, receiving a full internet route table, a BGP4 device may need to hold over a million routes. Many configurations,
especially those involving more than one neighbor, can require the device to hold even more routes. Brocade devices provide dynamic
memory allocation for BGP4 data. BGP4 devices automatically allocate memory when needed to support BGP4 neighbors, routes and
route attribute entries. Dynamic memory allocation is performed automatically by the software and does not require a reload.
The routes sent to and received from neighbors use the most BGP4 memory. Generally, the actual limit to the number of neighbors,
routes, or route attribute entries the device can accommodate depends on how many routes the device sends to and receives from the
neighbors.
In some cases, where most of the neighbors do not send or receive a full BGP route table (about 80,000 routes), the memory can
support a larger number of BGP4 neighbors. However, if most of the BGP4 neighbors send or receive full BGP route tables, the number
of BGP neighbors the memory can support is less than in configurations where the neighbors send smaller route tables.
Memory configuration options obsoleted by dynamic memory
Devices that support dynamic BGP4 memory allocation do not require or even support static configuration of memory for BGP4
neighbors, routes, or route attributes. Consequently, the following CLI commands and equivalent Web management options are not
supported on these devices:
• max-neighbors num
• max-routes num
• max-attribute-entries num
If you boot a device that has a startup-config file that contains these commands, the software ignores the commands and uses dynamic
memory allocation for BGP4. The first time you save the device running configuration (running-config) to the startup-config file, the
commands are removed from the file.
Basic configuration tasks required for BGP4
The following sections describe how to perform the configuration tasks that are required to use BGP4 on the Brocade device.
Enabling BGP4 on the device
When you enable BGP4 on the device, BGP4 is automatically activated. To enable BGP4 on the device, enter the following commands.
device# configure terminal
device(config)# router bgp
BGP4: Please configure 'local-as' parameter in order to enable BGP4.
device(config-bgp-router)# local-as 10
device(config-bgp-router)# neighbor 10.157.23.99 remote-as 100
device(config-bgp-router)# write memory
Memory considerations
Brocade FastIron Layer 3 Routing Configuration Guide
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