Filtering Subnets of a Summary Using the aggregate-address Command
Manual BGP route summarization, using the aggregate-address BGP router subcommand, provides the flexibility to allow none, all, or a subset of the summary’s component subnets to be advertised out of the BGP table. By allowing some and not others, the aggregate-address command can in effect filter some routes. The filtering options on the aggregate-address command are as follows: ■ Filtering all component subnets of the summary from being advertised, by using the summary-..
When the boot field is not a hex 0 or 1, routers choose the OS through the use of the boot system configuration command. If the configuration register calls for a full-featured IOS (boot field 0x2-F), the router reads the startup-configuration file for boot system commands. If present, the router tries each boot system command, in succession, until it finds an IOS to load. If there are no boot system commands, the router takes the default action, which is to load the first fi..
IGMP Snooping: Advanced Traffic Management
Life isn't perfect. Therefore, not everyone uses Cisco routers, even though they might use Cisco switches. What do you do if the user has non-Cisco routers in the system along with Catalysts? Or for that matter, what do other vendor products do with multicast frames? You cannot use CGMP in a non-Cisco environment because it is a Cisco proprietary feature. Many other vendors use a software feature where the switch processor examines each frame transferred through the switch. ..
You can use the following commands to restrict SNMP access to portions of the MIB tree. This example shows the legacy configuration method: Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#access-list 99 permit 172.25.1.0 0.0.0.255 Router(config)#access-list 99 deny any log Router(config)#snmp-server view ORAVIEW mib-2 included Router(config)#snmp-server view ORAVIEW at excluded Router(config)#snmp-server view ORAVIE..
Using NTP to Send Periodic Broadcast Time Updates
Use the NTP broadcast interface configuration command to enable server-side NTP broadcasts: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1(config)#clock timezone EST -5 Router1(config)#clock summer-time EDT recurring Router1(config)#ntp server 172.25.1.1 Router1(config)#ntp server 172.25.1.2 Router1(config)#interface FastEthernet0/0 Router1(config-if)#ntp broadcast Router1(config-if)#end Router1# To enable a NTP broadca..
