2126XM router and VLANS

[Jen]

This may have been answered already but I can't find it with a google or forum search so here goes.

I'm setting up a lab and have configured inter vlan routing on my 2 switches.  Everything is working fine until I hit the router.

So I log into the router, go into priv exec mode and type 'show vlan' to see where I am before configuring and get the bad command message (please note I'm not near the unit and don't remember letter for letter what it says).

Anyway with a little investigation it seems my router doesn't seem to understand the idea of vlans at all.

It tried with the vlan commands and the x.x.x.x xx syntax (again, not near the units or my notes so I may be slightly off on syntax here) but no joy and it seems that the sw version doesn't support it (I think i also need the IP Plus feature set).

So can anyone please point me at:

1) A way to update the router to handle vlans in one way or another (i did try searching for sw upgrades with no success).

2) A way on the switches (two 3600 series Layer 3 switches that very much understand vlans) to convert the packets to a format that the router will understand.

Now this may be me being a numpty, remember I'm doing this to learn Cisco, but up till now I've pretty much managed to work things out with a little prompting.  Port aggregation (both Cisco both LACP and Pagp), inter vlan routing, setting up SSH (or telnet in the case of the router, which doesn't support SSH), etc. So though I'm no expert I think I've got the basics down.

It's a 2126XM with 12.2(10r I think) on it. i can confirm this later today at about 20:30GMT.

[Jon Marshall]

You can do routing on a stick on the router but you need a certain feature set (think you may be right about IP Plus),

However if you have the routing between vlans on the swith(es) why not just connect the router to one of the switches using a L3 port on the switch and then just route between the switch(es) and the router ?

Jon

[Jen]

Errm , because I'm a numpty who didn't think of it? ;)  I was focusing so much on the router I forgot the switches already have the capability (wood, trees).

(Note to self, layer 3 switch means it's a router you pillock!)

I assume I set it up pretty much the same way I set up the router originally when I got it routing via NAT?  Port in on original subnet (in this case all of the switches ports as it's not a one in one out like the router), port out on different subnet, etc?

Not 100% sure how to do this without NAT (as I'd prefer not to NAT from switch to router then router to my main network) but I imagine if I go back over my notes it's pretty much the same config just with no NAT and a static external rather than DHCP. :)

I'm going to leave this not marked as correct for a little bit just in case someone also comes back with a 'go here and you can update the router', which I'd like to do anyway.  But assuming no answers of that type I think we've got it. :)

[Jon Marshall]

No problem, have done a similar things myself many times :)

Firstly I am not sure I understand the point about connecting the router to the switch. On most L3 switches you can have SVIs ("int vlan x") and the ports assigned to vlans or you can make a port a L3 port ie. "no switchport" and then assign an IP directly.

So I was suggesting a dedicated subnet between the switch and router and then you run a routing protocol or use statics.

In terms of NAT, again not clear, but just be aware nearly all Cisco switches don't support it.

In terms of updating the router have you tried to configure routing on a stick on it because you don't need to create the vlans first if I remember correctly.

Jon

[Jen]

Ok, so you know where I am.  I have three (well more, I even have one of the 1700 series (I think) phone system units)  but three in use) pieces of cisco kit and it's all for learning\doing lab work as I know HP but have little experience with Cisco and would like to add a CCNA to my bow.

I've segmented it off of the home network but am natting from the lab to the home network so I can both simulate logging on from the outside and so my lab can connect to the internet if needed.

So the physical layout is:

2126XM 2 port unit

  |

3600 24 port 10\100 with 2 Gigabit GBICS

 ||                               |     |     |

 ||                           10\100 Clients 

3600 24 port Gigabit switch

   ||          ||                 |     |      |

SAN   Hyper-V           Clients

So I need natting from the lab to the main network (which I assumed only the router can do), and the VLANs are just lab play.

I assumed I needed the router to understand the VLANs so I could set the ports to a VLAN trunk (as I have on the link between the two switches).

Now I'm trying new things as I learn new concepts and it may be that's hindering me a little as I'm layering on ideas as I go and backing up and starting from scratch might be a better bet.

It's sort of why I didn't think of your solution.  Started with the switches connected to the router on a flat subnet (no VLANs) and it all worked 100%.  Then after adding VLANs I hit a snag and my first thought was 'fixing' the problem piece of kit.

But bottom line this is a lab setup so a total nuke, reinstall and different way of handling the solution is always an option. :)

[Jon Marshall]

Your setup is fine as it is really.

I would then use a L3 connection between the top switch and the router and use NAT on the router as you suggest.

You are more likely to see this type of connectivity between the switch and the router in the real world than you are to see routing on a stick which is usually only used when you don't have any L3 switches in your LAN.

Jon

[Jen]

Thanks.  It's nice to know I'm on the right track.  Once I've finished training for the day (Rassin' frassin' Security+ ;) ) I'll pop home, spin up the lab and give it a try.

[Jon Marshall]

Any problems when you do just post back into this thread.

Jon