EGB failover in DMVPN

[UCrypto]

Dear Sir,

I am beginner in BGP. I would like to know about the EBGP .

 My Outbound traffic on CPE

All outbound traffic will go out thru primary line(12.1.3.1) 

 Inbound traffic  on CPE

All inbound traffic will come in thru primary line (12.1.3.1) . How to configure.

i referenced below link but my scenario is a little different.i want to use EBGP . Which configuration part do i need to change and edit ?

http://showipbgp.com/bgp-configurations/40-cisco/71-3-1-1-cisco-dual-bgp-with-metric-redundancy.html

• ISPs : 1
• WAN links : 2
• CPE : 1
• PE : 2

• Device : Cisco router with LAN/WAN ports.
• WAN1 / Serial IP : 12.1.3.0/30 (mask 255.255.255.252)
• WAN2 / Serial IP : 13.1.4.0/30 (mask 255.255.255.252)
• LAN / Ethernet IP : 10.1.0.1/24 and 10.1.0.129/25(Secondary)
• LAN : ISP (AS20) and Customer (AS65500)

[Larry Sullivan]

A route-map with weight to determine outbound traffic and as-prepends to determine inbound traffic.  You can also use M.E.D. if eBGP peerings are same AS on far end.

You can have a secondary route-map for the backup link with N prepends and weight lower than default and leave the primary without a route-map.  You would then have a failover route-map configured and ready to be applied.  It would have more as-prepends than the backup and a lower weight.

Or you could have a primary route-map on the primary and a less desirable route-map on the backup with a failover route-map ready to be applied to the primary.   

[UCrypto]

Hi ,
If i want to run DMVPN on this network,is it same way ?
In HUB site,I need to use different NHRP ID,different network for different ?
How to configure on spoke to HUB for failover ?

[Larry Sullivan]

Yes, this would work over DMVPN the same way.

HUB and Spoke should use same network ID in NHRP.  Tunnel IP should be same subnet.

Example failover:

route-map FAILOVER permit 10
 set metric 15000 (higher than secondary)

 set weight 50 (lower than secondary, cisco propriety)
 set as-path prepend 12345 12345 12345 12345 12345 12345 12345 (more hops than secondary)

And you would apply this in BGP configs

[UCrypto]

Hi ,
I would like to know if we use eBGP we can’t use dynamic neighbors so we’ll have to configure them manually each site ?

[UCrypto]

Hi ,
I would like to know,should i use loopback for ebgp peering ? or should i use physical interface address.Now i am using physical address.
In my design ,with attribute is best practice for BGP fail-over (weight or local preference)?
Can i configure without using as-prepend ?

[MrBeginner · Accepted solution]

Hi,

I always local-preference and prepend as below.

router bgp 65000
bgp log-neighbor-changes
network 2.2.2.0 mask 255.255.255.0
neighbor 10.1.12.1 remote-as 1
neighbor 10.1.12.1 route-map PREPEND out <===Primary Link
neighbor 10.1.12.1 route-map failoverlink in <==== Secondarily link
neighbor 12.12.12.1 remote-as 1

route-map failoverlink permit 10  
set local-preference 80 

route-map PREPEND permit 10
set as-path prepend 65000 65000