Layer 3 switching issue (or vlans?)

ashrobbo

ashrobbo

ashrobbo

Associate
Joined
3 May 2009
Posts
805
Hi All,

I've been tasked this week with implementing some Allied Telesis switches, these are for a fairly large IP camera setup. Kit isnt working so we have been drafted in to assist.

4AA9kAI.jpg


Heres the diagram,

for simplicity sake.

two switches - one connected to camera is a standard layer 2 allied telesis switch, ports with cameras connected are untagged in vlan30. Trunk port (port 1) is tagged in all vlans (10,20,30).

the other is an allied telesis layer 3 switch, it has 3 vlans (same ID's 10,20,30) and has an ip of .254 on each.

Cameras have a default gateway of 192.168.30.254
Laptop connected to an untagged port has a default gateway of 192.168.1.254

FOr some reason I cannot ping a camera on the .30 subnet, at all. Even if i change my ip address to 192.168.30.xx on the laptop and untag the port in vlan 30 on the layer 3 side i cannot ping the camera.

Other cameras work in the same setup (but not using allied telesis layer 2 switch on the camera side)

where am I going wrong?

Here's my scenario in detail

If laptop has 192.168.1.2 ip address
- I can ping 192.168.1254, 10.254, 20.254, 30.254 (all interfaces on L3 switch)
- I cannot ping any of the Cameras (192.168.30.2-4)
- L3 switch diagnostics cannot ping the cameras (192.168.30.2-4)
- I can access IP of the L2 switch (192.168.1.230) no issue at all
- Reboot of L2 or L3 switch doesn't resolve issue (if only!)

I know on a cisco you have to enable IP routing but i cant find any similar functionality on the allied telesis CLI, is there a dark secret somebody knows that I don't?

My next step is to setup a different switch with the same config and see if it works.

The layer 2 switch is situated 30ft in the air so ill need to get work permit etc sorted to access the switch directly and do any further testing.

Please help!

Ash
 
Can you ping the cameras from the L3 switch CLI?

Edit: Just saw that you can't. Are you sure your trunk is setup properly?
 
You are correct in that you need to set up the routing on your L3 switch.

Usually you create VLAN interface for this.

You've not given a model number but it'll be something like this on AT kit:

Code: 
interface vlan 30
ip address 192.168.30.254 255.255.255.0

I can't see any enable/disable IP routing commands in the manual, so I think that should do it but have a look at the manual for your specific switch.
 
blueboy2001 said:
You are correct in that you need to set up the routing on your L3 switch.

Usually you create VLAN interface for this.

You've not given a model number but it'll be something like this on AT kit:

Code: 
interface vlan 30
ip address 192.168.30.254 255.255.255.0

I can't see any enable/disable IP routing commands in the manual, so I think that should do it but have a look at the manual for your specific switch.
Click to expand...

Each vlan has an IP assigned to it - i know its doing my nut in!!

Model number is allied telesis x610-24ts

shouldn't a layer 3 switch route automatically being as it work sat layer 3? Seems silly it may need enabling as otherwise whats the point?
 
I am back on site tomorrow so will run a sh ip route and see what I get.

If I plug into the L3 switch directly and change a Port and IP to Untagged on VLAN30 all works as intended. IM also going to try a different L2 switch to see if it happens again, if so i guess im looking at an issue on the L2 switch (i may factory reset it and start fresh)
 
Connecting to the L3 switch with a port untagged on 30 shows the trunk is working, so your issue isn't with the L2 switch.

I'd say a route table will show you what's going wrong. You might be trying to send all traffic that isn't on-link to a router which doesn't know about the other subnets.
 
Here is said config and ip route

Codes: C - connected, S - static, R - RIP, B - BGP
O - OSPF, D - DHCP, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
* - candidate default

C 192.168.1.0/24 is directly connected, vlan1
C 192.168.10.0/24 is directly connected, vlan10
C 192.168.20.0/24 is directly connected, vlan20
C 192.168.30.0/24 is directly connected, vlan30

awplus#show running-config
!
service password-encryption
!
no banner motd
!
username manager privilege 15
no service ssh
!
service telnet
!
service http
!
no clock timezone
!
snmp-server
!
aaa authentication enable default local
aaa authentication login default local
!
ip domain-lookup
!
!
!
no service dhcp-server
!
no ip multicast-routing
!
spanning-tree mode rstp
!
switch 1 provision x610-24
!
vlan database
vlan 10 name VLAN10
vlan 20 name VLAN20
vlan 30 name VLAN30
vlan 10,20,30 state enable
!
interface port1.0.1-1.0.6
switchport
switchport mode trunk
switchport trunk allowed vlan add 10,20,30
!
interface port1.0.7-1.0.20
switchport
switchport mode access
!
interface port1.0.21-1.0.24
switchport
switchport mode trunk
switchport trunk allowed vlan add 10,20,30
!
interface vlan1
ip address 192.168.1.254/24
!
interface vlan10
ip address 192.168.10.254/24
!
interface vlan20
ip address 192.168.20.254/24
!
interface vlan30
ip address 192.168.30.254/24
!
!
line con 0
line vty 0 4
!
end
 
I'm surprised at the complete lack of any routing information in that config - there's no upstream gateway defined anywhere, no information about what interface it's on etc.
 
ashrobbo said:
shouldn't a layer 3 switch route automatically being as it work sat layer 3? Seems silly it may need enabling as otherwise whats the point?
Click to expand...

A layer 3 switch simply means it understands IP addresses. But it still needs to be told what to do with them.

Switches I've worked with usually need;

- an IP address on each vlan (which devices use as the default gateway)
- routing to be enabled on the switch itself
- A route for the switch itself to use to find non local traffic, i.e. the internet


For example on Dell Powerconnects, you'd use;

## Setup the IP address on the vlan and configure it for routing##
interface vlan 10
routing
ip address 10.100.0.1 255.255.255.0
exit



##Enable routing on the switch itself ##
ip routing



## Route for non local traffic ##
ip route 0.0.0.0 0.0.0.0 10.0.0.1
 
Well - I had enough couldnt find any information in regards to routing at all.

Therefore I simple set the entire port as untagged on VLAN30 and set the ip addresses of the devices all to 30

this worked but means i wont be trunking any other vlans, not an issue at the minute.
As soon as I put in a TP Link device, it all started working!

NIghtmare!
 
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