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amitkhera

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Connecting 2 LANs with different subnets using Nortel 2526t switch

I have 4 LANs with 4 switches which have the following IP addresses.
All computers in the 4 LANs have the same workgroup.
1.) 192.168.111.60
2.) 192.168.112.60
3.) 192.168.113.60
4.) 192.168.114.60

I want to connect the above 4 LANs with a Nortel 2526t switch. I want to be able to connect these LANs so that I can access the computers belonging to 1 LAN from another LAN.
I have plugged a cable from each of the above 4 switches into the Nortel 2526t switch. But its not working.
What do I need to do?
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Giladn
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do you have this switch configurations or is it brand new?

in general you need:

1. might need to use mask 255.255.255.0 on computers so you can access across those address
2. create a vlan in nortel 2526 using java device manager or CLI (via securecrt or similar)
3. attach the ports to that vlan.
4. save config

in addition, you can use TFTP server to upload and download config (I can provide) but you will still need to access via serial cable and CLI to configure the TFTP server.

try to access the switch via serial cable and type rw/rw for password and user, use command "en" to enable full access, then use "install" see if it solves you problem first..


Hope this helps,

G
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amitkhera

ASKER

I have done a factory reset on the switch and it has come to its default configuration.
I am using Hyperterminal to access the command line interface for the switch.

Now when I reboot the switch it brings me to its default command prompt. So it doesnt ask me for any usernames or passwords.
Where do I enter the rw/rw username and password? How do I create a VLAN?
Sorry I have never doen this before.
Okay I have found an article that tells me how to create a VLAN and how to add all the ports to it.

ERS-2526T# conf t
ERS-2526T(config)# vlan create 111 name VLAN-MGMT type port
ERS-2526T(config)# vlan configcontrol flexible
ERS-2526T(config)# vlan member add 111 all
ERS-2526T(config)# save config

This will create a VLAN called VLAN-MGMT and include all the ports into this VLAN.
Then can I plug a cable from all my 4 LAN switches into this Nortel switch and then all the computers connecting to these 4 switches should be able to communicate? Is that right or do I need to do something else?
You need to configure trunk connections between the switches because the computer IP addresses are in different segments. What model is the 4 LAN switches?
sorry for the delay -
yes, you need mgmt vlan (i.e vlan 222) and another vlan (i.e vlan 1) , mgmt vlan is for management and communication between the switches.
 vlan 222 is mgmt and is connecting to the other switches, i.e port 25 is member with vlan 222 and is configured as trunk (it passes all vlans configured for this port), in addition you have vlan 1 for example which is used for communication between computers, so port 25 has vid of 222 and is member of mgmt 222 and vlan 1 and has trunk property, all other ports should be access ports with vlan 1 that the computers connect to.
try the above, there are many configurations in addition but I think this should do it.
use different subnets for those vlans.
if you are still having problems I'll send a simple config which you can upload via CLI ( "enable" --> "configure(terminal)") by copying the commands to the terminal or via tftp server (requires communication with the tftp server).

Post back..

Gilad
Can you send me the config please
Hi,

Change the following fields in the text file according to your needs and upload all text in the file using the cli :

ip default-gateway 10.10.10.254  (can be your router/firewall address)

ip address netmask 255.255.255.0 (netmask for switches ONLY)

ip address switch 10.10.10.1    
(ip address allocated for the switches only, 2nd switch will be 10.10.10.2 etc.. )

then copy - paste all the text in the config file (execute "enable" --> "configure (terminal)"

connect switch to other switch/backbone using port 26
connect servers/desktops to ports 1-24


Post back..
Gilad
2526t.txt
Thanks Gilad.
I will try this out and get back to you.
Much appreciated,
Hi Gilad
Sorry to be a pain. Let me explain you the infrastructure again. And then can you tell me step by step what I need to do? I have never done this before so need to make sure that everything will work.
I have attached a jpeg that details my network. There is 2 LANs in the diagram.
I want to be able to communicate between Switch E and Switch F in the diagram so that I can have communication between LAN 1 and LAN 2.
Can you give me a step by step explanation please like do I need to create VLAN etc. or shall I just upload the config file to the 2 switches?

Many thanks
Drawing2.jpg
Hi,

You are not a pain:) it's better to ask then to assume..
thank you for the jpeg, it helps, as I see you have those 2 lans working - if it's working why can't  you connect for example port 24 on switch E  to port 24 on switch F? can you please check if it's working, it's not the best way to do it but you are using only 1 vlan so let's try before uploading the config..

Post back.

Gilad
Thanks Gilad.

I have not created any VLANs yet.
I plugged in a cable from Switch E to Switch F and it doesn't work.

Will I need to create a VLAN on both Switch E and Switch F and then connect them with the cable?
If yes, could you send me the exact commands I need to type in on both the switches to create the VLAN.

many thanks
Before that, how did you connect  between the 2 switches on lan 1/2 ?
Switch A and Switch B on LAN1 are not physically connected to each other.
Each computer on LAN1 has 2 network cards.

1st network card on each computer is configured with IP address 192.168.111.x
2nd network card on each computer is configured with IP address 192.168.112.x
Switch A is configured with IP address 192.168.111.x
Switch B is configured with IP address 192.168.112.x

A cable connects 1st network card from each computer to Switch A
A cable connects 2nd network card from each computer to Switch B

All this has been done to provide network card failover in our project.
This is how each computer on LAN1 can talk to any other computer on LAN1.
The same applies to LAN2.


So, the switches A/B and C/D are not physically connected to each other.

Many thanks
Amit
Any update Gilad ?

Many thanks

Amit
Hi amit,

This changes everything, I might have to change the config file, now I understand how they connect.  Just to make sure, you use subnet mask 255.255.255.0 on your network cards?
Yes I use subnet 255.255.255.0 on all network cards
Ok, do the following:

your switches should be on the same vlan so they can communicate - use the config file I gave you, when you deploy the config file change the ip address to 10.10.10.2 on the 2nd switch (no need to change on the 1st) , 10.10.10.3 on 3rd switch etc.. and change the gateway from 10.10.10.254 to 0.0.0.0 on every switch.

on your computers use the same subnet on both network cards (i.e for first nic 192.168.111.1/16  for the 2nd  192.168.112.1/16 ) that way they can be on the same vlan.
now you have 2 nic with same subnet and address pool and they can see each other and the switches can see each other as they are on a different vlan so less traffic and more security..

how to apply:

1. use your terminal to connect to switch A , execute the command "enable" press enter

2. execute command "config"  press enter (config "terminal")

2. now go to the config file and change the ip address for the gateway to 0.0.0.0 and leave 10.10.10.1 for this is the 1st switch.

3.mark all the text in the config file and right click --> copy

4. past the config to the terminal (right click--> paste)
notice all command executed successfully  and there is no terminal related error.

5. press ctrl+z you will go back to cli, execute command "save config"

6. execute command "write mem"

7. execute command "reload" and confirm.

now you have switch A with ip 10.10.10.1, ports 1-24 are all the same vlan and ports 25-26 are trunk and can be used to connect the switches to each other. do the same for switch B, then connect port 25 from switch A to port 25 on switch B, connect port 26 from switch B to port 25 on switch C and port 26 to port 25 on switch D.

try it first with LAN 1 (switches A,B) and test to see if you can ping NIC 1 from computer 1 to which is connected to switch A to NIC 1 from computer 2 that is connected to switch B. if ping is successful apply the config on LAN 2 and connect the switches with the ports stated above.

this should give you network cards and switch redundancy.
switch password and user is rw/rw.

I highly recommand backing up your current config, you can copy and paste to text file  when using command "show run" before doing any changes..

Post back..

Gilad
Wow.
I will read all this and will get back.

Thanks
Ready carefully.. post back for any q..
I have read your post above and it all makes sense now.
My only question is: Whats happened to Switch E and F in this equation? Do we not need them anymore?
Our project involves showing our client that Switch E and F are also being used for communication between LAN1 and LAN2.
do the same for E and F too, chaining them the same as the others should do fine..
you will have 1 Lan with redundancy which is what you require, no more 2 ends only one Lan that serves your needs.
I recommand not using E and F if you can because what will happen if one of them is down? you will not be able to get to LAN1/LAN2, as for your diagram you don't really need them for dividing to lan1 and 2 since there is only 1 now.
Thanks Gilad.
There is a slight twist. My fault. I have just found out that:

Switch A, B C and D are HP 2530 - 24G switches.

Switch E and F are the same as I mentioned before Nortel 2526t.


Is that going to change anything?

Sorry my fault. I should have checked this earlier.

Amit
Any update please Gilad
yes, there is a big diffrence since the configuration will not work on HP switches, you can connect them using the Nortel switch but that means a diffrent configuration file, I will check in the morning.
meanwhile you can apply the settings for your network cards this might solve everything.

Gilad
Sorry mate. I wasn't aware that it's a mix of hp switches as well. But I promise there is no other change now. Please help me connect these nortel switches with these hp switches. It will be a big help.  
Also what settings do you want me to apply on my network cards?

Thanks
Amit
Hi Gilad
I have got to connect all these switches by Tuesday morning mate. Our client is visiting next weekend. It will be a big help if you can help me sort this out please. Much appreciated.

Many thanks

Amit
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Giladn
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Ok cool. Done.
Hi Amit,

I have looked at the Hp whitepages I am not sure I know the config well enough to help, after changing the subnet mask on the computers are you able to reach from lan 1 to lan 2?
Hi Gilad
I have got no access to the computers until Tuesday morning because offices are closed here in the uk on Monday due to bank holiday.
Tuesday morning I will change the subnet for all the NICs and see if it works.  
In the meantime if you could come up with a config file to route between the nortel and hp switches that would be great.

Thanks
Amit
Thanks Gilad.

Your help is very much appreciated.
All working after changing the subnet masks. Brilliant.

Many thanks

Amit