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poweredge 3448 vlan trunking problem
I have two Dell 3448 switches on which I am trying to configure vlan.
First switch is connected to second switch using G3 port to second switch’s G4 port – this is for my normal LAN and its working fine.
I have configure port 41, 43, 45 as vlan access ports as vlan2, vlan3, vlan4 on first switch and port 47 as trunk port which goes to my layer 3 device ( checkpoint fw) and it relays the request to dhcp server on LAN and gets an IP address – working fine Now I have configured port 48 of the first switch to the second switch and configured it as trunk port which carry traffic of vlan2, vlan3, vlan4 to second switch.
On second switch I have configured same 41, 43, 45 port as vlan2, vlan3, vlan4 and port 48 as trunk port which is connected to second switch port 48 and carry traffic of vlan2, vlan3 and vlan4 on first switch.
The problem is that on first switch I am able to get IP address from my dhcp server on vlan ports, but not on second switch.
I am writing my switch config here.
First switch config:
console#
console# show run
interface range ethernet e(47-48)
switchport mode trunk
exit
vlan database
vlan 2-4
exit
interface ethernet e41
switchport access vlan 2
exit
interface range ethernet e(47-48)
switchport trunk allowed vlan add 2
exit
interface ethernet e43
switchport access vlan 3
exit
interface range ethernet e(47-48)
switchport trunk allowed vlan add 3
exit
interface ethernet e45
switchport access vlan 4
exit
interface range ethernet e(47-48)
switchport trunk allowed vlan add 4
exit
interface vlan 2
name vlan2
exit
interface vlan 3
name vlan3
exit
interface vlan 4
name vlan4
exit
interface vlan 1
ip address 10.10.21.21 255.255.255.0
exit
ip default-gateway 10.10.21.253
aaa authentication enable default line
aaa authentication login default line
line telnet
Default settings:
SW version 2.0.0.21 (date 15-Jan-2007 time 15:48:02)
Fast Ethernet Ports
==========================
no shutdown
speed 100
duplex full
negotiation
flow-control off
mdix auto
no back-pressure
Gigabit Ethernet Ports
=============================
no shutdown
speed 1000
duplex full
negotiation
flow-control off
mdix auto
no back-pressure
interface vlan 1
interface port-channel 1 - 8
spanning-tree
spanning-tree mode STP
qos basic
console#
Second switch config.
console# show run
interface ethernet e48
switchport mode trunk
exit
vlan database
vlan 2-4
exit
interface ethernet e41
switchport access vlan 2
exit
interface ethernet e48
switchport trunk allowed vlan add 2
exit
interface ethernet e43
switchport access vlan 3
exit
interface ethernet e48
switchport trunk allowed vlan add 3
exit
interface ethernet e45
switchport access vlan 4
exit
interface ethernet e48
switchport trunk allowed vlan add 4
exit
interface vlan 2
name vlan2
exit
interface vlan 3
name vlan3
exit
interface vlan 4
name vlan4
exit
interface vlan 1
ip address 10.10.21.22 255.255.255.0
exit
ip default-gateway 10.10.21.253
aaa authentication enable default line
aaa authentication login default line
Default settings:
SW version 2.0.0.21 (date 15-Jan-2007 time 15:48:02)
Fast Ethernet Ports
==========================
no shutdown
speed 100
duplex full
negotiation
flow-control off
mdix auto
no back-pressure
Gigabit Ethernet Ports
=============================
no shutdown
speed 1000
duplex full
negotiation
flow-control off
mdix auto
no back-pressure
interface vlan 1
interface port-channel 1 - 8
spanning-tree
spanning-tree mode STP
qos basic
console#
console#
Best regards,
V. Lelli"
First switch is connected to second switch using G3 port to second switch’s G4 port – this is for my normal LAN and its working fine.
I have configure port 41, 43, 45 as vlan access ports as vlan2, vlan3, vlan4 on first switch and port 47 as trunk port which goes to my layer 3 device ( checkpoint fw) and it relays the request to dhcp server on LAN and gets an IP address – working fine Now I have configured port 48 of the first switch to the second switch and configured it as trunk port which carry traffic of vlan2, vlan3, vlan4 to second switch.
On second switch I have configured same 41, 43, 45 port as vlan2, vlan3, vlan4 and port 48 as trunk port which is connected to second switch port 48 and carry traffic of vlan2, vlan3 and vlan4 on first switch.
The problem is that on first switch I am able to get IP address from my dhcp server on vlan ports, but not on second switch.
I am writing my switch config here.
First switch config:
console#
console# show run
interface range ethernet e(47-48)
switchport mode trunk
exit
vlan database
vlan 2-4
exit
interface ethernet e41
switchport access vlan 2
exit
interface range ethernet e(47-48)
switchport trunk allowed vlan add 2
exit
interface ethernet e43
switchport access vlan 3
exit
interface range ethernet e(47-48)
switchport trunk allowed vlan add 3
exit
interface ethernet e45
switchport access vlan 4
exit
interface range ethernet e(47-48)
switchport trunk allowed vlan add 4
exit
interface vlan 2
name vlan2
exit
interface vlan 3
name vlan3
exit
interface vlan 4
name vlan4
exit
interface vlan 1
ip address 10.10.21.21 255.255.255.0
exit
ip default-gateway 10.10.21.253
aaa authentication enable default line
aaa authentication login default line
line telnet
Default settings:
SW version 2.0.0.21 (date 15-Jan-2007 time 15:48:02)
Fast Ethernet Ports
==========================
no shutdown
speed 100
duplex full
negotiation
flow-control off
mdix auto
no back-pressure
Gigabit Ethernet Ports
=============================
no shutdown
speed 1000
duplex full
negotiation
flow-control off
mdix auto
no back-pressure
interface vlan 1
interface port-channel 1 - 8
spanning-tree
spanning-tree mode STP
qos basic
console#
Second switch config.
console# show run
interface ethernet e48
switchport mode trunk
exit
vlan database
vlan 2-4
exit
interface ethernet e41
switchport access vlan 2
exit
interface ethernet e48
switchport trunk allowed vlan add 2
exit
interface ethernet e43
switchport access vlan 3
exit
interface ethernet e48
switchport trunk allowed vlan add 3
exit
interface ethernet e45
switchport access vlan 4
exit
interface ethernet e48
switchport trunk allowed vlan add 4
exit
interface vlan 2
name vlan2
exit
interface vlan 3
name vlan3
exit
interface vlan 4
name vlan4
exit
interface vlan 1
ip address 10.10.21.22 255.255.255.0
exit
ip default-gateway 10.10.21.253
aaa authentication enable default line
aaa authentication login default line
Default settings:
SW version 2.0.0.21 (date 15-Jan-2007 time 15:48:02)
Fast Ethernet Ports
==========================
no shutdown
speed 100
duplex full
negotiation
flow-control off
mdix auto
no back-pressure
Gigabit Ethernet Ports
=============================
no shutdown
speed 1000
duplex full
negotiation
flow-control off
mdix auto
no back-pressure
interface vlan 1
interface port-channel 1 - 8
spanning-tree
spanning-tree mode STP
qos basic
console#
console#
Best regards,
V. Lelli"
you are connecting the 2 via g3 or g4
use Stacking and there will be no need for trunking as it will be one virtual switch
and it will be managed via one ip address
more efficient. the switches are current on firmware, so should not ahve an issue
Other than that, one link from switch to switch either a single port or LAG.
If you want multiple ports from vlan to vlan you ahve to use MST(multiple Spanning tree)
ues the lag
- thank you very much for your response.
I could see that one of the switch the vlan port is in blocking state that means that STP is working.
I tried disabling spanning tree and my network went down so I had to powercycle the switch and get back to original configuration.
can u pls.tell me the configuration of getting vlan trunk working between two switches. - I understand that two uplink between the switches will not work because of the STP. but my problem is to have the basic understanding of the configuration between two dell switches which have machines in vlan and Lan both.
I want to know how to configure LAg on vlans and if possible also to use MSTP between two switches.
if you could help me with the document - will be great.
thanks again.
Valter.
Well, if there are 2 uplinks it will work, STP will jsut block one until the other one is down.
But what you want is a LAG and set it up as a trunk to carry multiple vlans accross. Or so it appears.
You only need MST if you are linking a cable from each VLAN to its couneter part on each VLAN and the will not work using a LAG
Lag can only be a member of one vlan, or a trunk
I am not sure where or if there is a document.
Here is an example.
enable
configure
interface ethernet e1
channel-group 1 mode on
exit
interface ethernet e2
channel-group 1 mode on
exit
vlan database
vlan 2
vlan 3
exit
interface port-channel 1
switchport mode trunk
switchport trunk allowed vlan add 2,3
end
test configuration
boths sides need to have the same VLANS and LAGs configured.
Create the config before plugging in the cables or STP will block at least one of the ports.
this will allow 2 1 gigabit MAC sessions occur simultaniously giving you a virtual 2 gig throughput and carrying vlan1 untagged as native, vlan 2 and 3 tagged across the trunked port-channel
I am not going to try to walk through MST, maybe someone else will.
hope this helps
- sorry for troubling you again and again.
I have simple scenerio in front of me , and easy to understand .
- i have two dell 3448 switches A and B
- these switches are connected through g3 (A)- g4(B) switch port.
- my LAN ( 10.10.21.0) works just fine on these two switches.
- how can add vlan2 on both the switches and trunk so that machines on both the switch ( in vlan) can talk each other.
- when there is only one link between the switches ( vlan trunk) it work
- when I want to try with two uplink one for lan aready exists and other for vlan it does not work.
please let me know with example this simple configuration ( how to use lag in vlan) etc so that I can achieve the solution.
many thanks in advance.
let me know for more inputs.
regards,
Valter.
The configuration for a port-channel (LAG) is the same as for an individual port. Once a port is put in a port-channel, its individual port settings do not apply, only the port channel settings apply. Here is an example (on a 6024 not a 3448, but should be enough):
interface port-channel 1
switchport mode general
exit
vlan database
vlan 101-104
exit
interface range port-channel 1
switchport general allowed vlan add 101
exit
interface range port-channel 1
switchport general allowed vlan add 102
exit
interface range ethernet g(3-4)
channel-group 1 mode on
exit- do u mean if I only create one lag and include one port in it and setup it as a trunk, does my lan and vlan works on this on the both the switches.
I have practically three switches 3448 and then If possible i can connect g3-g3 of first and second switch and g4-g4 of first and third switch here. do u think both lan and vlan works in this configuration if I configure lan on all the three switches.
pls. respond.
thanks, - Hi,
thanks for the suggestion. I am able to configure LAG and used it as trunk and my lan and vlan worked properly.
I have three 3448 switches.
i have connected servers on central 3448 switch.
then I have connected my upper switch to central switch using g3-g3 port ( configure both g3 as LAG 1 and used it as trunk)
second I also want to connect my lower switch swith to central 3448 switch using g4-g4
- if i use the g4 of central switch also as the member of LAG and make it trunk and same g4 of lower switch as LAG1 and trunk as the configuration above - will this setup work ?
will it be right tringular config - while servers are on central switch and I used g3 and g4 of central switch to connect to respectively g3 and g4 of second and third switches.
please suggest.
thanks a lot for the help.
bh1633
909 Posts
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Posted February 13th, 2008 14:00
You have a loop as far as spanning tree is concerned.
You said you have g3 and e48 connected between the 2 switches. These switch default to a single 802.1d spanning tree. This means spanning tree will not pay attention vlans. Spanning tree will disable the slower port and use the g3 port.
Since g3 is in vlan 1 and g48 is in vlans 2,3,4, you can disable spanning tree on one of these ports on one of the switches without danger of creating a real loop in the network.