VLAN

[christew]

I have two 2821 with the NM-ESW16 modules. I have the two NM-ESW16 in a trunk configuration. Now I need to have a vlan that that is configured on the router to attach to the router gi0/1 interface. Normally this would not be an issues since I would manually plug in a cable from a switch to the router port and make sub interfaces (router on a stick), but with this module I would not think I would run a cable from the module to a port on the router.

Ideas?

[kwillacey]

Are you saying that the g0/1 port you are referring to and the NM are in the same 2821?

If so then you would probably be better off creating a vlan interface on the router and connect hosts or devices to ports assigned to that vlan.

[christew]

Yes the are in the same 2821.

[kwillacey]

In that case if you have multiple vlans you need to route then you will need an svi for each. You would not need the physical interface to do that.

int vlan 1

ip address 1.1.1.1 255.255.255.0

int vlan 2

ip address 2.2.2.2 255.255.255.0

and so on and assign each port to the required vlan. hth

[christew]

Once my vlans are configured and the ports on the NM-ESW6 are put in the right vlans, how do I connect the vlan to a router port such as gi0/1? Normally Gi0/1 would be a trunk port with subinterfaces for each vlan, but that involves a physical cable. Since this is in a single unit I would think I would not need a physical cable.

[kwillacey]

as mentioned before you will have no need to connect the g0/1 port to a port on the NM in order to router packets between the vlans in this case your router will be acting somewhat like a l3 switch.

What are you trying to accomplish? What will you be connecting to the NM?

[christew]

Thanks. I'm trying to work out the configurations for a fail over using hsrp with the two 2821's I have.

2821's in two different locations with layer 2 connection between them.

Router A (2821)Interface Fa1/15 connects to Router B (2821) as a trunk and interface gi0/0 (on both routers) connect to the external network. (service provider)

Router A is vtp server

Router B is vtp client

Clients are connected to either 2821 NM module and are on the same VLAN 192.168.1.x

Have NAT on both routers (given that the external address space is different) not and issue.

Run EIGRP on external interfaces network only, so router know if external network is down

HSRP configured for gi0/1 on both routers

Router A - ip address 192.168.1.100

Router B - ip address 192.168.1.200

standby ip address 192.168.1.254

Here is the question, how do I make the VLAN work to a physical routed interface for hsrp to work?

[kwillacey]

Let me see if I get this right you have two different locations each with a connection to the same external network. These two locations are then connected via a trunk, the end users are connected to the NM and are all on the same vlan.

You want to setup HSRP so that location A's 2821 is the active router for both location A and B? Is that correct?

If so then lets say your only vlan is vlan 1 then you will need to create a vlan 1 interface on both routers and configure the HSRP parameters on them as normal and make location A's router the active device. HSRP can work on vlan interfaces as well.

int vlan 1

ip address 192.168.1.100 255.255.255.0

standby 1 ip 192.168.1.254

standby 1 priority 110

standby 1 preempt

int vlan 1

ip address 192.168.1.200 255.255.255.0

standby 1 ip 192.168.1.254

standby 1 preempt

hth

[christew]

Thanks that is what I was thinking, but since router b is a vtp client how can I create another vlan on router B?

I created the vlan and issued the "show ip route" and no routes to those network show up.

Do I need to make sub interfaces off gi0/1 for the vlan and put the hsrp configuration there?

[kwillacey]

a vlan or a vlan interface? if you need another vlan let's say vlan 20 you can create it on router A through the vlan database and it should be sent to router B via vtp. You can then assign ports to each router to vlan 20 and create a vlan interface which will act as the gateway for vlan 20. Check out example below.

router a

---------

vlan database

vlan 20

exit

int fa1/16

switchport mode access

switchport access vlan 20

int vlan 20

ip address 192.168.20.100 255.255.255.0

standby 1 ip 192.168.20.254

standby 1 priority 110

standby 1 preempt

router b

--------

int fa1/16

switchport mode access

switchport access vlan 20

int vlan 20

ip address 192.168.20.200 255.255.255.0

standby 1 ip 192.168.20.254

standby 1 preempt

hth

[kwillacey]

also once you have created the vlan interfaces and issue a 'sh ip route' you should see each interface as a directly connected network.

[christew]

Thanks, seems to be working now.

[kwillacey]

no problem be sure to rate it as solved