What is address family ipv4 in BGP?
The address-family command defines BGP behavior for each specific supported case. The most common address families are ipv4 unicast and ipv6 unicast . The other possible choices supported in this version are ipv4 multicast and ipv6 multicast .
How do I set local preference attributes in BGP?
BGP Local preferences can be applied in 2 ways –
- R3(config)# ip prefix-list net4 4.4.4.0/24.
- R3(config)# route-map PREF permit 10.
- R3(config-route-map)# match ip address prefix-list net4.
- R3(config-route-map)# set local-preference 300.
- R3(config)# router bgp 1.
- R3(config)# neighbour 192.168.35.5 route-map PREF in.
Why use BGP local preference?
You can use local preference to configure your autonomous system to select a certain exit point. Instead of configuring weight on each router you can use local preference because it is exchanged on all internal BGP routers. By increasing the local preference to 800 we can make AS 1 send all traffic towards AS 2.
What is the difference between weight and local preference in BGP?
You can use weight instead of local preference to influence the selected path to external BGP peers. The difference is that weight is configured locally and is not exchanged in BGP updates. On the other hand, the local preference attribute is exchanged between iBGP peers and is configured at the gateway router.
What is the difference between local preference and Med?
BGP Local Preference Atribute says to the internal neighbours, “How to Exit AS”. BGP MED Attribute says to the external neighbours, “How to Enter AS”. MED (Multi Exit Discriminator) attribute is applied to the outbound interface and shows the best inbound interface into its AS (Autonomous System).
What does address family IPv4 do?
Now, the address-family ipv4 declares neighbors with whom we want to exchange normal IPv4 unicast routes. This may be surprising because to exchange IPv4 routes with a neighbor, it is sufficient to simply define that neighbor by its address.
What is the difference between VPNv4 and IPv4 address family?
When the customers packets are being received by PE they become labeled one and to forward labeled packets to different PE/RR; address-family vpnv4 is required. In short we can say that ipv4 address-family is being used for customers and vpnv4 address-family is used by SP core.
What is the difference between local preference and weight?
What is the difference between weight and local preference?
What is MED attribute in BGP?
The BGP multiple exit discriminator (MED, or MULTI_EXIT_DISC) is a non-transitive attribute, meaning that it is not propagated throughout the Internet, but only to adjacent autonomous systems (ASs). The MED attribute is optional, meaning that it is not always sent with the BGP updates.