Using SLA for gateway of last resort for specific subnet

[TRACY HARTMANN]

I am trying to get a ip SLA to change the gateway of last resort for a specific subnet.  This is what I have so far...

 IP SLA

ip sla 10
icmp-echo 10.20.0.90 (router I want to be gateway of last resort for specific subnets

ip sla schedule 10 life forever start-time now
route-map last_resort permit 10
match ip address test

ip access-list extended testzscaler
permit ip host 10.3.20.2 any  ( just trying one address for now)

ip local policy route-map zscaler_last_resort
ip classless
ip route 0.0.0.0 0.0.0.0 10.20.0.90 track 10  Only for specific subnets
ip route 0.0.0.0 0.0.0.0 10.20.0.1 200   Default for everyone else

If I trace from the switch everything goes out the 10.20.0.90.  However I just want the 10.3.20.2 to go that way.

Tracy

[rais]

I don't know how SLA could help.

You should either use PBR or vrf

HTH.

[TRACY HARTMANN]

I have a 3750 and the command i want to use is set ip default next-hop but that doesn't work on a 3750.   I am trying to find a different way to do the same thing.   What would be an example of a VRF?  Sorry I haven't used one of those.

[rais]

There has to be a router/L3 switch in your network. How will 10.3.x.x  go to 10.20.x.x subnet?

Thanks.

[TRACY HARTMANN]

This is a layer 3 switch, it just does not accept the ip default next-hop command.  That is why I am looking for a different way to do what I need.

[Deepak Kumar]

Hi,

Here I noticed that you didn't applied correct acl under the route-map. The ACL name is different.

As you mentioned that set default gateway command is not working so did you tried with "Set next-hop ...." Command.

If it is not working then please verify the switch IOS version and Switch SDM templete. 

Regards,

Deepak Kumar

[TRACY HARTMANN]

Sorry I shortened the ACL name when I copied it over but it is correct on my switch.

I have been told that the set ip default next-hop is not an available on the 3750 no matter the ios.   That is why I am trying to do the same thing but with a SLA.

the sdm is desktop routing

Thanks

[Deepak Kumar]

Hi,

I checked documents and it is available on 3750 switch but keep in mind that you need some things to be ready

SDM Template:

Desktop dual IPv4 and IPv6 routing template

Licenses/IOS Image:

You need IPservices to be able to do PBR, verify with sh version | i IOS

IP Routing:

Must be enabled on the switch.

Regards,

Deepak Kumar

[Jon Marshall]

Which documents did you check ? 

I have just checked the latest configuration guides and it is still listed as an unsupported command. 

Can you provide a link to where it says it is supported ?

Jon

[Deepak Kumar]

Hi,

Here is the link: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/release/15-0_2_se/configuration/guide/scg3750.pdf

Page number: 1056

and

http://cisco2960.over-blog.com/2013/12/cisco-3750-switch-pbr.html

Regards,

Deepak Kumar

[Jon Marshall]

Neither of those links mention "set ip defaut next-hop ..." command which is what is needed if you want to use the routing first and then the PBR next hop. 

Jon

[TRACY HARTMANN]

I have ip routing on, the sdm prefer is desktop routing and I have ip servers.  PBR does work on the 3750 but not the specific command ip default next-hop..

If there is something else I need to do to get it to work that would be great, otherwise I need a different way to do it.  Again I am trying to have the gateway of last resort to be different for a specific subnet.

Thanks

[TRACY HARTMANN]

I have ip routing on, the sdm prefer is desktop routing and I have ip servers.  PBR does work on the 3750 but not the specific command ip default next-hop..

If there is something else I need to do to get it to work that would be great, otherwise I need a different way to do it.  Again I am trying to have the gateway of last resort to be different for a specific subnet.

Thanks

[Georg Pauwen]

Hello,

can you post your full config ? It might be easier to explain what I have in mind when I can add the lines mentioned, seeing your full configuration...

[TRACY HARTMANN]

Below is what I have configured with SLA since I don't think I can use the ip default next-hop...If I can I will add that configuration underneath the SLA one

 IP SLA

ip sla 10
icmp-echo 10.20.0.90 (router I want to be gateway of last resort for specific subnets

ip sla schedule 10 life forever start-time now
route-map last_resort permit 10
match ip address test

ip access-list extended testzscaler
permit ip host 10.3.20.2 any  ( just trying one address for now)

ip local policy route-map zscaler_last_resort
ip classless
ip route 0.0.0.0 0.0.0.0 10.20.0.90 track 10  Only for specific subnets
ip route 0.0.0.0 0.0.0.0 10.20.0.1 200   Default for everyone else

If I trace from the switch everything goes out the 10.20.0.90.  However I just want the 10.3.20.2 to go that way.

*****************

Config with PBR

ip access-list extended testzscaler
permit ip host 10.3.20.2 any
permit ip host 10.30.20.1 any

route-map zscaler_last_resort permit 10
match ip address testzscaler
set ip default next-hop 10.20.0.90

on the interface I place the ip policy but because we are on a 3750 it doesn't show up or work unless I take the word default out on the next hop in the route-map,