Now I have lease line links to 2 ISPs for internet connection. I separate packets of users by accesslist such as www go to ISP1 and mail or other protocol go to ISP2 . Let's say link go to ISP1 down I need www traffics failover to ISP2 and vice versa.
Problem is acl on nat statement?
If you config about this.
access-l 101 permit tcp any any www -->www traffic to ISP1
access-l 101 permit tcp any any mail --> back up for mail packet to ISP2 down
access-l 102 permit tcp any any mail -->mail packet to ISP2
access-l 102 permit tcp any any www --> back up for www traffic go to ISP2
ip nat inside source list 101 interface s0 overload
ip nat inside source list 102 interface s1 overload
In this case is links of ISP1 and ISP2 are UP.
when you apply this acl on nat statement then nat will process each statement in order( if I incorrect please correct me) so mail traffics will match in this acl and then nat with ip of ISP1 only.
You best bet is to use routemaps on the nat statements to do this rather than the access lists.
You match the nexthop and use that to select the proper nat. In effect with a interface overload configuration you say use the interface that that traffic is going out of as the nat address for this traffic.
You control which path to select either by policy routing or normal routing.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.