Urgent Help please help

The_guroo_2 · ‎05-08-2008

Guys i have one 3350 switch and two routers cisco 878.....the routers are attached to the swicth via LAN (layer 2) ports of the router (which is builin) now i have created 2 vlans 10,11 on the 3350 swicth and assigned the port to it (which connects the routers) now i want to ping one router from other (different Vlans) can someone please tell m ehow it will be as the swicth port in the router is layer two i cant assignm IP address and my design required that the router shd connect to the swicth via layer 2 port which is builtin???? what shd i do can someone please help

Jon Marshall · ‎05-08-2008

Is the 3550 acting as a layer 2 switch only ?.

If you want to be able to communicate between the 2 routers then either

1) You need both routers to have their interfaces in the same vlan and allocate an IP address for each router interface out of the same subnet

or

2) You need to enable inter-vlan routing on your 3550 switch to route between the 2 vlans. If your switch is running SMI software it can only act as layer 2 switch. If it is running EMI software you make it responsible for routing between the 2 vlans.

Jon

The_guroo_2 · ‎05-09-2008

Jon

my swicth is EMI and i have created two vlans interfaces as well as vlans on them......now my one router shd be in one vlan and the other should be in other.....the inbuilt swicth port from both the routers are connected to swicth and i have mak ethe swicth ports of 3550 meeber of vlans already the problem is how i am going to configure the routers to ping each other i have no problem with 3550 or how i m gonna configure inter vlan routing.......what shd be configs on routers????

Jon Marshall · ‎05-09-2008

You need to tell each router how to reach the others subnet. So lets say

router1 -> subnet 192.168.5.0/24 -> vlan 10

router2 -> subnet 192.168.6.0/24 -> vlan 20

The 3550 knows about both these subnets but each router only knows about it's directly connected interface ie. it's own subnet.

So either

1) Run a dynamic routing protocol between the 3550 and each router

or

2) Add static routes to the routers eg.

router1

ip route 192.168.6.0 255.255.255.0 <3550 vlan 10 ip>

router2

ip route 192.168.5.0 255.255.255.0 <3550 vlan 20 ip>

Jon

Pravin Phadte · ‎05-09-2008

check if this solution works.

config t

vlan 10

ip address (for vlan 10)

config t

vlan 20

ip address (for vlan 20)

config t

ip routing

The_guroo_2 · ‎05-10-2008

Jon

so it means that i have to create vlan interfaces on the router as well??? as the cable is attached to swicth port which doesnt take any ip address???? it has lan interface but our design says that it shd be attached to the 4one of the 4 switch ports???