I have got a fact about routing enabled on C3550.

[sirisak.c]

my network

6509

|

|

3550(1)-------3550(2)

|

|

2950

vtp domain on 6509 is "NET1" and

vtp domain on 3550(1),3550(2),2950is "NET2"

3550(1) enable "ip routing" command,3550(2)-L2,no L3

From 6509 to 3550(1) is the Vlan 40,when i set to trunk,it doesn't work.

Some questions-

if I enable "ip routing" command, I have to configure ip address for

any interface that connect to the core network,right?

3550(1),(2),and 2950 are running on Vlan1,(it's a flat network)

Once,I have tried to configure L3 on 3550(2),then I cannot remote to 3550(2)

when i disable "ip routing" command(only on 3550(2)),3550(1) still running L3

,it's work, i can remote to 3550(2).

My intention- (vtp domain -6509(NET1)vtp domain-3550(1),(2),2950(NET2))

I will disable "ip routing" command on 3550(1)

and set connection between 6509 and 3550(1) to trunk.

and set vlan 1 for management on 3550(1),(2),2950

set vlan 10 for 3550(2),vlan 20 for 2950.....

any opinion , any suggestion,,,

please help me ...

thanks in advance...

[htaluja_2]

Routed interfaces are created on 3550 as SVIs...for instance for vlan 10...the routed interface would be:

interface vlan 10

ip address x.x.x.x y.y.y.y

Since 3550 and 6509 are in different vtp domains, you will have to create same vlans twice.

Configure trunk. Ensure native vlans are same on either side.

Choose Spanning Tree roots [according to your topology]

Things should work.

[sirisak.c]

Thanks for your reply.. and

do i have to enable "ip routing" command on 3550(1)???

when is the "ip routing" command is necessary???

I have heard that c3550 cannot work like 3COM Corebuilder

for Layer 3

[Prashanth Krishnappa]

You'll need IP routing to route across the switch(static routes, routing protocols).

3550 can be a full fledged router. Substantiate on what the 3550 could not do which Corebuilder can, let us know

[rjackson]

The 3550 is a router when it has the correct image (EMI) and ip routing has been enabled with "ip routing". It routes between vlans as described above using virtual interfaces like; INT VLAN1, INT VLAN2 which each have IP addresses. Ports assigned to vlans 1 and 2 are routed through the virtual interfaces and do not have ip addresses on the phyisical interfaces.

In addition individual ports can be "pulled out of the switch" and made into traditional router ports using the interface command "no switchport access". These ports are not in any vlan and can then have ip addresses assigned to the physical interface.