12-24-2011 09:56 PM - edited 03-04-2019 02:44 PM
I have a 2801 with dual ISP connections, and I have configured route-maps to direct voice traffic over ISP1 (working just fine), and I'm attempting send all other traffic over ISP2 (traffic is load-balancing instead). The connection to ISP2 is DHCP, and I have configured a route-map to route this traffic using the 'ip next-hop dynamic dhcp' command, but when I look at the route-map, it states the following:
ip next-hop dynamic dhcp - current value is UNKNOWN
Is there something that I need to enable in order to see the next-hop, and properly send traffic over the ISP2 connection?
Configured:
route-map TrafficSplit permit 10
match ip address VoIPNetwork
set ip precedence priority
set ip next-hop XXX.XXX.XXX.XXX
!
route-map TrafficSplit permit 20
match ip address LocalNet
set ip next-hop dynamic dhcp
Show Output:
route-map TrafficSplit, permit, sequence 10
Match clauses:
ip address (access-lists): VoIPNetwork
Set clauses:
ip precedence priority
ip next-hop XXX.XXX.XXX.XXX
Policy routing matches: 12772 packets, 10978067 bytes
route-map TrafficSplit, permit, sequence 20
Match clauses:
ip address (access-lists): LocalNet
Set clauses:
ip next-hop dynamic dhcp - current value is UNKNOWN
Policy routing matches: 997611 packets, 1398419458 bytes
Cisco IOS Software, 2801 Software (C2801-ADVENTERPRISEK9-M), Version 12.4(22)YB8, RELEASE SOFTWARE (fc1)
Thanks,
-Ed
Solved! Go to Solution.
12-28-2011 10:41 AM
Glad to help Ed, and thanks for the update.
Can you please mark the threat as resolved, so other people can benefit from it?
Reza
12-25-2011 12:00 PM
Ed,
Can you do a "sh ip arp" on your device and figure out the IP address that is assigned to you by provider2? Then instead of set ip next-hop dynamic dhcp use set ip next-hop XXX.XXX.XXX.XXX and see if traffic is being divided correctly.
obviously, this would not be a permanent solution, but will tell us if the issue is the DHCP statement in the route map or not.
HTH
12-25-2011 08:29 PM
Ed
I would suggest a somewhat different approach for you. Instead of having two route maps you might have one route map for the Voice traffic through ISP1 and have a default route to ISP 2 for all other traffic. If you want failover then a floating static default route should be possible.
HTH
Rick
Sent from Cisco Technical Support iPad App
12-25-2011 09:16 PM
Reza-
Great idea... not sure why I didn't think of that!
When I put the next-hop as suggested, the traffic does appear to go as planned. All of the voice traffic over ISP1, and all the other over ISP2... so the route-map is definitely not seeing the DHCP assigned gateway.
An additional thing I noticed is that when I checked my default routes (show ip route), the DHCP gateway was no longer listed (it was previously).
When I Initially Checked:
S* 0.0.0.0/0 [1/0] via XXX.XXX.XXX.XXX
After Bouncing the DHCP Interface:
S* 0.0.0.0/0 [1/0] via XXX.XXX.XXX.XXX
[1/0] via XXX.XXX.XXX.XXX
So there definitely seems to be an issue with DHCP and it's gateway address... any ideas???
-Ed
P.S. - You can see the DHCP gateway by using the 'show dhcp lease' command.
12-25-2011 11:26 PM
Hi Ed,
As long as the IP address you are getting from your ISP2 is dynamic, why dont you sent the interface instead of IP address in command set ip next-hop.
Please rate the helpfull posts.
Regards,
Naidu.
12-26-2011 08:23 AM
Hi Naidu,
Specifying an interface is not an option:
have a look:
Switch(config-route-map)#set ip next-hop ?
A.B.C.D IP address of next hop
dynamic application dynamically sets next hop
in-vrf VRF for VPNv4 nexthop
peer-address Use peer address (for BGP only)
verify-availability Verify if nexthop is reachable
Switch(config-route-map)#set ip next-hop
The only set interface I see is under interface and not ip:
Switch(config-route-map)#set interface ?
Async Async interface
Auto-Template Auto-Template interface
BVI Bridge-Group Virtual Interface
CTunnel CTunnel interface
Dialer Dialer interface
FastEthernet FastEthernet IEEE 802.3
Filter Filter interface
Filtergroup Filter Group interface
GigabitEthernet GigabitEthernet IEEE 802.3z
GroupVI Group Virtual interface
Lex Lex interface
Loopback Loopback interface
Null Null interface
Port-channel Ethernet Channel of interfaces
Portgroup Portgroup interface
Pos-channel POS Channel of interfaces
TenGigabitEthernet Ten Gigabit Ethernet
Tunnel Tunnel interface
Vif PGM Multicast Host interface
Virtual-Template Virtual Template interface
Virtual-TokenRing Virtual TokenRing
Vlan Catalyst Vlans
fcpa Fiber Channel
Switch(config-route-map)#set interface
HTH
12-26-2011 08:38 AM
Ed,
Looking at the Command Reference Guide, it indicates that this command was integrated in IOS 12.3(8)T and 15.0(1)M.
Looking at your verstion, you are not running T revision. So, I am wondering if an upgrade to T or 15 could resolve the issue. If none of these help, then the easiest solution might be to request a static IP from the ISP.
HTH
12-26-2011 06:50 PM
I'm not sure I see the correlation between it being in a 'T' revision, and the revision I'm running now. If the command is present it should function as expected. I was thinking that this might be a bug with the way it's behaving.
I'm fine with upgrading, but I'd like to know that it will resolve the issue, and that this is in fact not normal behavior.
Thanks Reza.
12-28-2011 09:59 AM
Problem resolved by upgrading to Version 12.4(25f)... thanks for everyone's input.
-Ed
12-28-2011 10:41 AM
Glad to help Ed, and thanks for the update.
Can you please mark the threat as resolved, so other people can benefit from it?
Reza
09-02-2019 06:08 AM
This is an 8 year old question, but thw answer will save you time and grief in solving the router-map next-hop dynamic dhcp issue.
I found that rebooting the router after configuring "next-hop dynamic dhcp" in a route-map will pull the gateway from the dhcp source.
This makes sense since there is no command to tell the route-map to make a dhcprequest for a gateway until a reboot occurs. Works after initial reboot and all subsequent reboots. Tested on Cisco 891, 881, 871, 1841s with 12.x and 15.x codes.
09-08-2019 06:45 AM
This is absolutely correct, in fact issuing "release dhcp gi0/x" works as well. However it still pulls in the same dhcp settings for both statements.
before
route-map PBR, permit, sequence 10
Match clauses:
ip address (access-lists): 101
Set clauses:
ip next-hop dynamic dhcp - current value is 47.185.16.1
default interface GigabitEthernet0/1
Policy routing matches: 86673 packets, 13061504 bytes
route-map PBR, permit, sequence 20
Match clauses:
ip address (access-lists): 102
Set clauses:
ip next-hop self
ip next-hop dynamic dhcp - current value is 47.185.16.1
default interface GigabitEthernet0/2
Policy routing matches: 9173 packets, 782973 bytes
After
INET-2921-RT#sh route-map PBR
route-map PBR, permit, sequence 10
Match clauses:
ip address (access-lists): 101
Set clauses:
ip next-hop dynamic dhcp - current value is 35.134.112.1
default interface GigabitEthernet0/1
Policy routing matches: 86673 packets, 13061504 bytes
route-map PBR, permit, sequence 20
Match clauses:
ip address (access-lists): 102
Set clauses:
ip next-hop self
ip next-hop dynamic dhcp - current value is 35.134.112.1
default interface GigabitEthernet0/2
Policy routing matches: 9173 packets, 782973 bytes
I am still working on this problem. If anyone has any new input please let me know.
My Config:
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/1 dhcp 10 (this needs to be removed ultimately, but allows my internet to work currently)
!
ip sla auto discovery
ip sla 1
icmp-echo 47.185.16.1 source-interface GigabitEthernet0/1
ip sla schedule 1 life forever start-time now
!
route-map PBR permit 10
match ip address 101
set ip next-hop dynamic dhcp
set default interface GigabitEthernet0/1
!
route-map PBR permit 20
match ip address 102
set ip next-hop dynamic dhcp
set default interface GigabitEthernet0/2
!
route-map NAT_ISP2 permit 10
match ip address 102
match interface GigabitEthernet0/2
!
route-map NAT_ISP1 permit 10
match ip address 101
match interface GigabitEthernet0/1
!
Thank you!
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