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New Member

1841 and 4 port Switch

I have some 1841 routers in a network, each has a 2 port E1 WAN module and a 4 port Ethernet Switch module. If I create VLANs on the switch module - what do I do for a trunk port. I want my VLAns to go out on the WAN port to another router. Can the E1 WAN port be a trunk port between 2 routers that have switching modules in them. I have read the config guide but it doent help

many thanks

Bob

  • Other Network Infrastructure Subjects
17 REPLIES
Purple

Re: 1841 and 4 port Switch

Hi Bob,

Are you running frame-relay on that WAN link ? If so, one option you could have is to bridge each VLAN over a separate DLCI on that WAN link.

The following link describes how you can bridge using IOS:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cg/hbrn_c/part05/ch05/index.htm

Pls do remember to rate posts.

Paresh

New Member

Re: 1841 and 4 port Switch

Its a real E1 transmission link. The switch module book shows how to set up the VLAns but doesnt indicate how the router will then process them, and which port can be the trunk.

Purple

Re: 1841 and 4 port Switch

You could try something like the following:

router 1

--------

bridge irb

!

int fast0/0

switchport access vlan 10

!

int fast0/1

switchport access vlan 20

!

int fast0/2

switchport access vlan 30

!

interface vlan10

ip address ....

bridge-group 10

!

interface vlan20

ip address ....

bridge-group 20

!

interface vlan30

ip address ....

bridge-group 30

!

interface serial1/0

encapsulation frame-relay

frame-relay intf-type dce

frame-relay lmi-type q933a

!

interface serial1/0.16 point-to-point

frame-relay interface-dlci 16

bridge-group 10

!

interface serial1/0.17 point-to-point

frame-relay interface-dlci 17

bridge-group 20

!

interface serial1/0.18 point-to-point

frame-relay interface-dlci 18

bridge-group 30

!

bridge 10 protocol ieee

bridge 10 route ip

!

bridge 20 protocol ieee

bridge 20 route ip

!

bridge 30 protocol ieee

bridge 30 route ip

router 2

--------

bridge irb

!

int fast0/0

switchport access vlan 10

!

int fast0/1

switchport access vlan 20

!

int fast0/2

switchport access vlan 30

!

interface vlan10

ip address ....

bridge-group 10

!

interface vlan20

ip address ....

bridge-group 20

!

interface vlan30

ip address ....

bridge-group 30

!

interface serial1/0

encapsulation frame-relay

!

interface serial1/0.16 point-to-point

frame-relay interface-dlci 16

bridge-group 10

!

interface serial1/0.17 point-to-point

frame-relay interface-dlci 17

bridge-group 20

!

interface serial1/0.18 point-to-point

frame-relay interface-dlci 18

bridge-group 30

!

bridge 10 protocol ieee

bridge 10 route ip

!

bridge 20 protocol ieee

bridge 20 route ip

!

bridge 30 protocol ieee

bridge 30 route ip

Explanation:

- interfaces Fast0/0, 0/1 and 0/2 are placed in VLANS 10, 20 and 30 respectively.

- each of those VLANs has an SVI interface (i.e. interface vlan) created on each router

- VLAN 10 is bridged over the WAN link using DLCI 16

- VLAN 20 is bridged over the WAN link using DLCI 17

- VLAN 30 is bridged over the WAN link using DLCI 18

Pls do remember to rate the posts ...

Paresh

New Member

Re: 1841 and 4 port Switch

Many thanks - this is looking very close to what I need. Each of the Switchport module ports needs to have an Ip address, and I need to get these networks to the second router over the E1 WAN link. What I do not see in the manual, is how the VLans are trunked - and to which Router port

thanks

Bob

Purple

Re: 1841 and 4 port Switch

Bob,

The E1 interface is effectively acting as an ethernet trunk to the other router. Is that what you question was ?

Pls do rate the posts to show your appreciation for people who take the time to help you solve your issues.

Paresh

New Member

Re: 1841 and 4 port Switch

Yes - I'm not sure if I need the bridge port. What I'm trying to do is route the different VLAns on each of the 4 switchport modules, via the E1 WAN link.Normally on a switch I would have to have a trunk port, but this is a routerwith a switch built in, so I'm not sure if the same rules apply. Do I still need the bridge setup you described.

Many thanks - I will rate all posts, I did not mean to show any lack of appreciation

Bob

Purple

Re: 1841 and 4 port Switch

Oh ok, so you mean that you want to configure each of the FasEthernet ports as a trunk, do you ? If so, you should be able to configure them as trunks as you would do on a 'real' switch. Have I understood you correctly ? Is it these FastEth ports you want to configure as a trunk ?

You certainly do need the bridge setup since there is no other way of passing Ethernet traffic over an E1 link...

Re: rating - that was not directed at you specifically. I am a frequent poster and I tend to put in requests for people to rate posts since there are a lot of people out there who benefit from our replies but don't bother to go back and rate the posts. In any case, thanks for rating :-)

Paresh

New Member

Re: 1841 and 4 port Switch

I'm explaining myself badly. I have an 1841 which has an E1 WAN module, a 4 port Fast Ethernet switch module, and 2 built in Fast Ethernet ports. The WAN port is connected to another router over an E1 link. I want to put equipment on each of the Ethernet ports, each with an IP address (so thats 6 ports in total). There is a server attached to the second router which has to be able to access each of the 6 IP addresses.

Now I can handle the 2 built in Ethernet ports, but its the 4 ports on the Switch module that are confusing me as I can only give them IP addesses if each port is in a VLAN - but how do I make them visible to the upstream router.Do I make the WAN port on the router a trunk link for the switch ports. The manula is not much help

Hope that has explained it better. I really appreciate your input

regards

Bob

Purple

Re: 1841 and 4 port Switch

Ok, Bob. Now that's made things a lot clearer !

There are two options, the solution of each of which depends on your exact requirements. The two possiblities that I see are:

1. The 6 devices you have at your first site are all part of the same IP network, 192.168.1.0/24 e.g. 192.168.1.1, 192.168.1.2, 192.168.1.3 and so on till 192.168.1.6.

Secondly, the server at the other site is on a different network e.g 192.168.10.1

2. All your devices including your server, are on the same network: 192.168.1.0/24 e.g. 192.168.1.1, 192.168.1.2, 192.168.1.3 and so on till 192.168.1.7 (server's IP)

From your posts, it appears that you are familiar with LAN switching but not routing, but I could be wrong on this. The better solution here is to use routing so that the "trunk", as you call it, is a routed trunk, not a switched trunk. Given that, I would say that option 1 from above is better suited to your environment.

Let me know whuch way you wanna go and I can help you with the config...

Paresh

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