11-20-2011 08:31 AM - edited 03-04-2019 02:20 PM
Hi everybody.
I have similar configuration as mister here https://supportforums.cisco.com/message/3494977#3494977 but slighlty different problem.
Let's start.
I have CISCO 2911 device. It has 3 GigabitEthernet interfaces and we bougt one more FastEthernet interface for DMZ.
One GE is LAN interface and other two are WAN interfaces (with one of them is assigned DMZ interface set on FastEthernet). So here is the problem. Everything worked just fine until last week. Idea of this configuration is that most traffic is flowing through one WAN interface and some of critical traffic must go through another (mostly some of VPN connections), and eventually that other link need to work as backup link if first one fails.
Now is the problem. I cannot go out through backup link. EXEPT. We set some of services through nat and everybody can access to them from outside?! I debugged some nat translations and saw that there is translation from our side to wan but nothing is returning back?!
Here is config :
Current configuration : 47956 bytes
!
! Last configuration change at 15:58:50 Prague Wed Nov 16 2011 by belit_adm
!
version 15.0
no service pad
service tcp-keepalives-in
service tcp-keepalives-out
service timestamps debug datetime msec localtime show-timezone
service timestamps log datetime msec localtime show-timezone
service password-encryption
service sequence-numbers
!
hostname Gateway
!
boot-start-marker
boot-end-marker
!
security authentication failure rate 3 log
security passwords min-length 6
logging buffered 51200
logging console critical
enable secret 5 $1$..gV$.hcKrK27/A4SHnV9Nyo6N0
enable password 7 11044B5C54515E0E576E6F
!
aaa new-model
!
!
aaa authentication login local_authen local
aaa authorization exec local_author local
!
!
!
!
!
aaa session-id common
!
!
!
clock timezone Prague 1
clock summer-time Prague date Mar 30 2003 2:00 Oct 26 2003 3:00
!
no ipv6 cef
no ip source-route
no ip cef
!
!
!
!
no ip bootp server
ip domain name domain.local
ip name-server 21.16.2.1
!
multilink bundle-name authenticated
!
parameter-map type ooo global
tcp reassembly queue length 64
tcp reassembly memory limit 4096
!
!
!
license udi pid CISCO2911/K9 sn FHK1431F2Y0
!
!
username admin privilege 15 secret 5 $1$miqR$D2cXHh21ml8adQahjRj/g/
!
redundancy
!
!
ip tcp synwait-time 10
ip ssh authentication-retries 5
ip ssh version 1
!
!
!
!
!
!
!
!
!
interface Null0
no ip unreachables
!
interface GigabitEthernet0/0
description LAN$FW_INSIDE$
ip address 172.28.42.5 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat inside
ip virtual-reassembly
ip policy route-map MWOut
duplex auto
speed auto
no mop enabled
!
!
interface GigabitEthernet0/1
description WAN 1
mac-address 000c.29e3.c57f
ip address 1.2.3.4 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
no mop enabled
!
!
interface GigabitEthernet0/2
description WAN 2
ip address 5.6.7.8 255.255.255.252
no ip redirects
no ip unreachables
no ip proxy-arp
ip flow ingress
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
no mop enabled
!
!
interface FastEthernet0/0/0
description DMZ$FW_OUTSIDE$
ip address 12.12.12.12 255.255.255.248 secondary
ip address 23.23.23.23 255.255.255.248
no ip redirects
no ip unreachables
no ip proxy-arp
ip flow ingress
ip policy route-map DMZOut
duplex auto
speed auto
no mop enabled
!
!
!
ip forward-protocol nd
!
ip http server
ip http access-class 1
ip http authentication local
no ip http secure-server
ip flow-top-talkers
top 25
sort-by bytes
cache-timeout 2500
!
ip nat inside source static tcp 172.28.42.183 1723 interface GigabitEthernet0/1 1723
ip nat inside source static tcp 172.28.42.233 1723 interface GigabitEthernet0/2 1723
ip nat inside source static tcp 172.28.42.4 443 interface GigabitEthernet0/2 443
ip nat inside source static tcp 172.28.42.4 25 interface GigabitEthernet0/2 25
ip nat inside source static tcp 172.28.42.185 80 interface GigabitEthernet0/2 80
ip nat inside source static tcp 172.28.42.143 80 interface GigabitEthernet0/1 80
ip nat inside source route-map WAN2-NAT interface GigabitEthernet0/2 overload
ip nat inside source route-map WAN1-NAT interface GigabitEthernet0/1 overload
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/1 15
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/2 16
ip route 9.15.6.11 255.255.255.255 GigabitEthernet0/2 4
!
!
logging trap debugging
access-list 1 permit 172.28.42.0 0.0.0.255
access-list 1 deny any
access-list 2 remark CCP_ACL Category=18
access-list 2 deny 172.28.42.183
access-list 2 deny 172.28.42.192 0.0.0.63
access-list 2 permit 172.28.42.0 0.0.0.255
access-list 3 remark CCP_ACL Category=18
access-list 3 deny 172.28.42.183
access-list 3 deny 172.28.42.192 0.0.0.63
access-list 3 permit 172.28.42.0 0.0.0.255
access-list 101 remark Auto generated by SDM Management Access feature
access-list 101 remark CCP_ACL Category=1
access-list 101 permit ip 172.28.42.0 0.0.0.255 any
access-list 130 permit ip 12.12.12.1 0.0.0.7 any
access-list 130 permit ip 23.23.23.1 0.0.0.7 any
access-list 131 permit ip 172.28.42.192 0.0.0.63 any
access-list 131 permit ip host 172.28.42.4 any
access-list 131 permit ip host 172.28.42.185 any
!
no cdp run
!
!
!
route-map DMZOut permit 30
match ip address 130
set ip next-hop 1.2.3.3
!
route-map WAN2-NAT permit 10
match ip address 2
match interface GigabitEthernet0/2
!
route-map WAN1-NAT permit 10
match ip address 3
match interface GigabitEthernet0/1
!
route-map MWOut permit 20
match ip address 131
set ip next-hop 1.2.3.3
When I try to connect ot VPN server at 9.15.6.11 I cannot connect until route is set over interface GE0/1. Is there any idea how to solve the problem?
NOTE:
All interfaces on router are OK. I double check all of them. On provider side everything is OK exept they had some problem on the night when my config stopped to work. BUT. When I connect laptop to interface belongs to WAN2 ISP everything is working just fine, so I suppose that only problem here is my configuration.
Solved! Go to Solution.
11-23-2011 08:27 AM
Hi,
a route-map used for NAT overloading on 2 different WAN interfaces must have a match interface command or match ip next-hop but not a set ip next-hop command.
I still don't understand why you want this AD of 4 for the static host route, you can leave the default of AD 1 as there are no equal longest match static routes for this destination.
Regards.
Alain
11-20-2011 03:53 PM
You say you have moved some routes to the other link but has your service provider also moved the appropriate return routes.
Sounds like asymmetric routing where it's going out one link but being sent back via the other original link hence you'd only see nat translations in one direction. Anything stateful in between such as firewalls are not going to like that either.
Get a copy of your routes from your ISP to see where they are sending traffic to your outside translated addresses, it could be they are all pointing still on your original link!
Sent from Cisco Technical Support iPad App
11-23-2011 04:49 AM
Well, I called my ISP ad they did something with their layer3 switch so we are now on diffrent VLAN. That's their explanation so I'm not able to tell if they are wrong or not. Anyway problem is solved when I changed in my route from "GigabitEthernet0/2" to ip address of my next hop for my isp. That is fine but now I have another problem. Now I cannot access to anything on WAN 1 link. When I remove static route ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/1 15 everything goes through WAN 2 link and when I bring that route back Internet doesn't work at all. I tried to set my next hop address from another ISP as I did for WAN 2 link but no luck so far. I'm starting to pull my hair off... There is new configuration:
interface GigabitEthernet0/0
description LAN
ip address 172.28.42.5 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat inside
ip virtual-reassembly
ip policy route-map MWOut
duplex auto
speed auto
no mop enabled
!
!
interface GigabitEthernet0/1
description WAN 1
ip address 1.2.3.4 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
no mop enabled
!
!
interface GigabitEthernet0/2
description WAN 2
ip address 5.6.7.8 255.255.255.252
no ip redirects
no ip unreachables
no ip proxy-arp
ip flow ingress
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
no mop enabled
!
!
interface FastEthernet0/0/0
description DMZ
ip address 2.3.4.5 255.255.255.248 secondary
ip address 4.5.6.7 255.255.255.248
no ip redirects
no ip unreachables
no ip proxy-arp
ip flow ingress
ip policy route-map DMZOut
duplex auto
speed auto
no mop enabled
!
!
!
ip forward-protocol nd
!
ip http server
ip http access-class 1
ip http authentication local
no ip http secure-server
ip flow-top-talkers
top 25
sort-by bytes
cache-timeout 2500
!
ip nat inside source static tcp 172.28.42.233 1723 interface GigabitEthernet0/2 1723
ip nat inside source static tcp 172.28.42.203 1723 interface GigabitEthernet0/1 1723
ip nat inside source route-map WAN2-NAT interface GigabitEthernet0/2 overload
ip nat inside source route-map WAN1-NAT interface GigabitEthernet0/1 overload
ip route 0.0.0.0 0.0.0.0 1.2.3.1 15
ip route 0.0.0.0 0.0.0.0 5.6.7.1 16
ip route 91.150.67.11 255.255.255.255 5.6.7.1 4
!
!
logging trap debugging
access-list 1 permit 172.28.42.0 0.0.0.255
access-list 1 deny any
!
access-list 2 deny 172.28.42.192 0.0.0.63
access-list 2 permit 172.28.42.0 0.0.0.255
!
access-list 3 deny 172.28.42.192 0.0.0.63
access-list 3 permit 172.28.42.0 0.0.0.255
!
access-list 101 permit ip 172.28.42.0 0.0.0.255 any
!
access-list 130 permit ip 2.3.4.0 0.0.0.7 any
access-list 130 permit ip 4.5.6.0 0.0.0.7 any
!
access-list 131 permit ip 172.28.42.192 0.0.0.63 any
access-list 131 permit ip host 172.28.42.4 any
access-list 131 permit ip host 172.28.42.185 any
!
access-list 132 permit ip host 172.28.42.203 any
!
!
!
route-map DMZOut permit 10
match ip address 130
set ip next-hop 5.6.7.1
!
route-map WAN2-NAT permit 10
match ip address 2
set ip next-hop 5.6.7.1
!
route-map WAN1-NAT permit 10
match ip address 3
match interface 1.2.3.1
!
route-map MWOut permit 5
match ip address 132
set ip next-hop 1.2.3.1
!
route-map MWOut permit 10
match ip address 131
set ip next-hop 5.6.7.1
!
!
end
Note that yet again everything from outside to inside is going through NAT to both interfaces as it should.
Message was edited by: Ivica Vujovic
11-23-2011 06:29 AM
Hi,
1)you're referencing 2 route-maps in your NAT overload config but I don't see them anywhere else in the config?
EDIT: I need new pair of glasses EDIT2: No no I can keep this one
2) why are you changing AD of this static route, it isn't necessary. EDIT: just a remark not correcting the behaviour, forget about it.
ip route 91.150.67.11 255.255.255.255 5.6.7.1 4
Regards.
Alain
11-23-2011 06:33 AM
Sorry, I forgot to change also in nat overload. I edited configuration to match actual.
Regarding route
ip route 91.150.67.11 255.255.255.255 5.6.7.1 4
I added lower AD so I can prioritize traffic to go through WAN 2 link and not through WAN 1.
Idea is to put almost all traffic through WAN 1 and some critical traffic through WAN 2. And WAN 2 link i s also backup link if route to WAN 1 fails.
11-23-2011 06:44 AM
Hi,
route-map WAN2-NAT permit 10
match ip address 2
set ip next-hop 5.6.7.1 ----> it should be match interface
route-map WAN1-NAT permit 10
match ip address 3
match interface 1.2.3.1 ----> this isn't an interface id
ip route 0.0.0.0 0.0.0.0 1.2.3.1 15 ---> WAN1
ip route 0.0.0.0 0.0.0.0 5.6.7.1 16 ---->WAN2
These are both longest match routes and the second one having a higher AD will not get installed in the routing table unless first one fails, is this what you want? Now the NAT to WAN2 won't work then because there is no route for forwarding traffic to this interface.
Regards.
Alain
11-23-2011 06:46 AM
Hi,
it's not a lower AD but higher as the default is 1 and when there is only one static route that is the longest match , AD is not taken into account.
Regards.
Alain
11-23-2011 07:09 AM
That's right. Second one is not active untill first one fails. Also there is third ip route as it's traffic witch should go through WAN 2, hense AD is 4.
Regarding
route-map WAN2-NAT permit 10
route-map WAN1-NAT permit 10
you suggest I should use match interface GigabitEthernet0/x instead set ip next-hop x.x.x.x?
EDIT: WAN 2 link is OK, but at the moment WAN 1 is not translating as it should. I will try with match interface to see if there is any result.
11-23-2011 08:27 AM
Hi,
a route-map used for NAT overloading on 2 different WAN interfaces must have a match interface command or match ip next-hop but not a set ip next-hop command.
I still don't understand why you want this AD of 4 for the static host route, you can leave the default of AD 1 as there are no equal longest match static routes for this destination.
Regards.
Alain
11-23-2011 09:04 AM
You're right. There is no need for setting AD, I actually don't know why I put it there. Probably was to tired to think about that.
Also you were right about match interface. That solved my problem. I hate when I can't see forest because of one tree. Thank's.
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