Email notifications stopped working after adding 2nd ISP -asymmetrical?

[Darren Spezio]

e-mail notifications and scan to e-mail from the copiers stopped working after adding second ISP using NATing, both use aspmx.l.google.com, regular e-mail communcation between users work fine. I'm guessing the routing is asymmetrical , what can I do to make it symmetrical ?

ISP was added for additional bandwidth. As soon as I remove the 2nd IP route, the email notifications and scan to email start working again.

Cisco 2900

interface GigabitEthernet0/0
description Outside-LightPath
ip address 173.x.162 255.255.255.252
duplex auto
speed auto
!
interface GigabitEthernet0/1
description To Firewall
ip address 69.x.209 255.255.255.240
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
!
interface GigabitEthernet0/2
ip address 108.x.146 255.255.255.252
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
ip http timeout-policy idle 60 life 86400 requests 10000
!
ip nat inside source list 50 interface GigabitEthernet0/2 overload
ip route 0.0.0.0 0.0.0.0 173.x.161
ip route 0.0.0.0 0.0.0.0 108.x.145
!
access-list 50 permit 69.x.211
!
no cdp run

!
!
control-plane
!
banner motd ^C
This equipment is privately owned & operated.
It is for AUTHORIZED USE ONLY!
All access to this equipment is logged.
DISCONNECT IMMEDIATELY if you are not an AUTHORIZED User.
Violators will be prosecuted to the fullest extent of the law.
^C
!
line con 0
login local
line aux 0
line vty 0 4
login local
transport input ssh
!
scheduler allocate 20000 1000
ntp server 128.118.25.5
end

[Darren Spezio]

Philip, 

I was wondering if you can help me create a failover between the 2 ISPs, just in case the primary should go down. I will gladly open another discussion, but I would ask if you can grab it - please let me know.

Darren

[Philip D'Ath]

Please open up a fresh discussion and post a link to it.

[Darren Spezio]

Here you go, thank you.

https://supportforums.cisco.com/discussion/13092331/failover-2-isps

[Pawan Raut]

NAT should work fine when outgoing packets and incoming packed are on same  L3 interface of router or Firewall. In other word forward traffic and reverse traffic should be symmetrical else it will not work.

If you have two ISP and you need it to works as Active/Active then you should use policy base routing this will resolved your asymmetric routing issue and NAT issue will resolved.

Below articular will help you to understanding how to set up NAting on dual ISP link. If you need any assistance to set up design or config plesae let me know. Also Rate the post if you found it useful .

https://supportforums.cisco.com/document/32186/dual-internet-links-nating-pbr-and-ip-sla

Regards,

Pawan (CCIE# 52104)

[Darren Spezio]

Would you be able to look over the latest output file I posted about an hour ago, it has policy base routing.