3750 IP Route /48

[CobbyJ]

Hello,

We have a 3750 and trying to add a /48 to ip route, it accepts the command but it does not work or work as a gateway, it does work as a /64 though.

We are running the following

12.2(55)SE12 C3750-IPSERVICESK9-M

Is there anything i can do to make it work, or would i just need a switch upgrade?

Any help would be greatly appriciated.

[marce1000]

 - Please provide the command that you tried and or executed. 2) When you say it does not work as a gateway : how is this experienced , provide screenshots (e.g.) 3) Check logs on the switch  after the particular command is tried.

 M.

[CobbyJ]

Hello,

So im thinking its an issue with the ospf v3

I have the following set on the vlan

ipv6 address 2A03:F80:99::1/48

and OSFv3

ipv6 router ospf 2000
 router-id 4.4.4.4
 log-adjacency-changes
 area 0 range 2A03:F80:99::/48
 default-metric 25
 redistribute connected
 redistribute static

When i try to ping out from 2A03:F80:99::1/48 i cant reach anything but i can if i do 2A03:F80:99::1/64

my client wants to have multiple /64's and use 2A03:F80:99::1/48 as the gateway.

The issue i think its its not picking up the route

This is the sh ipv6 route from our BGP router

S   2A03:F80:99::/48 [1/0]
     via Null0, directly connected

Any ideas on what the issue is and what i can do to fix it?

[Harold Ritter]

Hi @CobbyJ ,

Using anything other than a /64 on a user subnet is not recommended. It will break SLAAC among other things. This is probably why you can't ping the workstations from the router. Why would you want to assign a /48 on the user subnet? Can you explain the requirement?

Regards,

[CobbyJ]

I 100% agree, its what our client wants, and im just trying to make it work.

their idea is to have multiple /64's for clients and point them to /48 gateway

[Harold Ritter]

Hi @CobbyJ ,

You probably need to challenge your customer on this one. Since SLAAC is not going to work, they would either need to statically configure the workstations or use DHCP. But in my view it is better to understand why they would want a /48 assigned to a single vlan and address their requirement accordingly.

Regards,

[CobbyJ]

I said the same and they need to use the gateway from their /64 subnet.

They want to give each of their clients a /64, they explained if they get banned from google they block the /64 and not a /48 so one client would not impact another.

Also another issue i found is when they did a /64 it would not work or pick it up unless i did ip route for that specific /64 - how would i get around that so it will route anything under the /48?

[MHM Cisco World]

redistribute static SUBENT  <<- you need only this keyword

[CobbyJ]

I dont have that option

only these

metric Metric for redistributed routes
metric-type OSPF/IS-IS exterior metric type for redistributed routes
route-map Route map reference
tag Set tag for routes redistributed into OSPF