HELP setting up 2724 and 2716 for spanning VLANs

Question

I just recently purchased the 2 x 2724 and 2 x 2716 PowerConnect switches for obvious reasons.  They seem to be running great except for  one problem I seem to be having Interconnecting the switches such that the VLANs I have are correctly spanning all the switches because most traffic traverses between switches for the same VLAN but it seems that complete communication between switches on the same VLAN does not happen.  I am used to Nortel Baystack switches and their function/feature of 'InterSwitch' ports.  I have done this on the PowerConnect switches but I seem to be having a very weird problem that I can not figure out.   My configuration: 2724 with the following VLANs: 1, 101, 202, 301, 401 ports 23 and 24 under VLAN Port settings are set to PVID 1 and under VLAN Membership these ports are Tagged for all the VLANs ports 1-4 are set to lets say VLAN 202 with 1 and 2 setup on the LAN side of a pair of redundant firewalls and 3 and 4 setup to a pair of servers   2716 with the exact same configuration as above with the exception of ports 23 and 24 being 15 and 16 ports 1-4 are setup to servers   My problem: Between these 2 switches VLAN 202 for instance can ping devices on the other switch with the same VLAN but some RPC communication is not being forwarded between them ie. Active Directory Replication information.  The problem goes away if I connect the servers in the same VLANs to the SAME switch  To make matters worse ALL servers no matter what switch they are connected on that VLAN CAN connect to the firewall with no problems at all going in or out of the network.   My question is how exactly should I be setting up the Interswitch ports on these 2724 and 2716 switches?  Is my configuration incorrect?  Do these switches have limitations on doing this?   Any help would be greatly appreciated! Thanks, Roger

fungirog · Answer

Please help I am still having a problem with this.   A detailed specific guide into setting this up so that VLANS span across the two switches would be great just so I can very my config.   Please someone give me some feedback / help.   Thanks, Roger

DELL-Randy · Answer

For configuring the PowerConnect 2700 series switches to communicate multiple VLANs, you will need to have the interfaces that interconnect the switches configured in each of the VLANs as Tagged. This will ensure the 802.1Q VLAN information is forwarded.

Additionally, you may need to configure the PVID for your Access Ports. For instance, interfaces 1-4 configured with a VLAN ID of 202 should also have a PVID of 202 configured as well.

Essentially, the VLAN ID is the 802.1Q information that is appended to the Ethernet Frame when traffic is forwarded. When an Ethernet Frame is received without any 802.1Q information, the interface appends the PVID as the 802.1Q information.

fungirog · Answer

Ok Dell-Randy.  I do believe I have everything setup as you suggested and still no dice.  Please Please Please help me get this working as I know it should.   Here are the exact settings: VLAN 202 is 172.16.0.0/24 (172.16.0.0 255.255.255.0)   - 2724 Switch - Interface Configuration for all ports are set as default which is admin status enabled, auto negotiation enabled, back pressure disabled, flow control disabled Jumbo Frames disabled VLAN Membership      VLAN ID 1 = untag egress ports for 1 and 19 - 24      VLAN ID 101 = untag egress ports for 3 - 7 and tag egress ports for 23 - 24      VLAN ID 202 = untag egress ports for 8 - 13 and tag egress ports for 23 - 24      VLAN ID 213 = untag egress ports for 2 and tag egress ports for 23 - 24      VLAN ID 301 = untag egress ports for 14 - 18 and tag egress ports for 23 - 24 VLAN Port Settings with all ports set with Frame Type Admit All and Ingress Filtering Enabled      PVID 1 = ports 1 and 19 - 24      PVID 101 = ports 3 - 7      PVID 202 = ports 8 - 13      PVID 213 = ports 2      PVID 301 = ports 14 - 18 LAG Membership None setup All other settings left alone.   - 2716 Switch - Interface Configuration for all ports are set as default which is admin status enabled, auto negotiation enabled, back pressure disabled, flow control disabled Jumbo Frames disabled VLAN Membership      VLAN ID 1 = untag egress ports for 15 -16      VLAN ID 101 = tag egress ports for 15 - 16      VLAN ID 202 = untag egress ports for 1 - 14 and tag egress ports for 15 - 16      VLAN ID 213 = tag egress ports for 15 - 16      VLAN ID 301 = tag egress ports for 15 - 16 VLAN Port Settings with all ports set with Frame Type Admit All and Ingress Filtering Enabled      PVID 1 = ports 15 - 16      PVID 101 = none      PVID 202 = ports 1 - 14      PVID 213 = none      PVID 301 = none LAG Membership None setup All other settings left alone   The ports I am using for interconnecting the switches are 24 on the 2724 and 16 on the 2716.   My servers are setup in VLAN 202 and the majority of them are connected to the 2716 switch directly.  The firewalls protecting those servers are connected to the 2724 and are of course also in VLAN 202 on the private side of the firewall.  Again on VLAN 202 you can ping any device no matter what switch that device is connected to but that seems to be where the communication stops ... well sort of.  Any other type of communication does not span VLAN 202.  For instance I log directly into one of the servers that is connected to the 2716 switch and I am unable to connect to the firewalls web based admin interface but if I move that same server and connect it to the 2724 where the firewalls are connected I can get to the firewalls web based admin interface.  Now again to make matters worse is that the web sites and other services that are being served through the firewalls to those servers CAN be accessed just fine from the Internet or outside the firewall no matter what swtich the servers are connected to.  I have tried changing the cables, hard coding duplex and some other things but nothing helps.  Again to recap and to explain the problem simpler is that when  I connect 2 windows or linux does not matter servers to the same switch on VLAN 202 they can fully communicate but when I connect one server to a port on VLAN 202 from switch 2724 and then connect the other server to a port on VLAN 202 from switch 2716 they can not fully communicate.  The CAN ping each other in that scenario but that is it.  Again I have ports 24 and 16 interconnecting the two switches.   I know I must be missing something or have a minor detail mis configured but I am at my wits end and I desperately need your assistance.   Thank You.   Roger

DELL-Randy · Answer

What device is routing between the VLANs?  From what I understand, the firewalls are attached to untagged interfaces on VLAN 202.  Ping connectivity is indicative that the system is forwarding the dot1q information, thus is communicating across the tagged link.   In addition, I understand that there are a total of (4) PowerConnect 2700 series switches in the topology.  Are the Tagged links on the 2716 and 2724 for uplinking the PowerConnect switches together as follows?                                        | 2724 |                                     /            \                               | 2716 |    | 2716 |                                    \            /                                      | 2724 |   If so, this will be an issue as you have created a loop on devices that do not support the Spanning Tree protocol.  This would also account for the intermittent connectivity.  The VLAN configuration -- per your post -- appears to be correct for passing the dot1q information between the PowerConnect 2700s.

fungirog · Answer

Oh yeah that last 2724 is being used in another office unmanaged.  And a Sonicwall Pro 300 firewall is being used between VLANs but even if you take that device out of the picture and just use the servers I run into the same problem on the Dell switches and not others.   Thanks, Roger

fungirog · Answer

Ok here is how it is configured:   |--2724--|              | - port 24 on 2724             | - port 16 on 2716             |--2716--|              | - port 15 on 2716             | - port 16 on 2716             |--2716--|   From the 2724 port 24 connects to port 16 on the middle layer 2716 and then port 15 of that switch connects to the last layer 2716 on its port 16.   So let's say I have a Windows Web server connected to port 8 (VLAN 202) on the 2724 and then I have another different Windows Web server connected to port4 (VLAN202) on either the middle layer or last layer 2716.  Now with that config in mind setup as I have mentioned in a previous thread, I can ping one Windows Web server from the other and vice versa but I am unable to connect to a website in either direction.  When I move both servers to the same VLAN on the same switch all communication works as it should.  Of course since both web servers are on the same VLAN they are in the exact same subnet lets say 172.16.0.0/24.  I must also say that I have this EXACT config on other layer2 switches and they don't experience this same problem when communicating between the switches.  One thing I have noticed for the default VLAN on on the VLAN Membership section of the Dell switches is that I can not set that VLAN to be Tagged on the Inter-Switch ports.  On other vendors switches I am able to do that.  Don't think that would make a difference but it IS the only difference I can see between any of my lab testing.  I also do not have 1.0.0.44 installed yet on any of these switches but I will be trying that soon just in case.  Oh if you want to mimic my config the switch IP addresses are being assigned by a DHCP server and they get 172.20.0.241, 172.20.0.242, 172.20.0.243 using a subnet mask of 255.255.255.0.  Again VLAN 202 is using the 172.16.0.0/24 IP space.  Hope this helps you figure this out for me.   Thanks, Roger

fungirog · Answer

Dell Support,

Please help with this I am STILL having this problem. Basically what I need to know for the 2724 and 2716 is what exact settings should these switches ports have that actually connect to another switch?

Let's say port 24 on the 2724 and port 16 on the 2716 are interconnected. I assume I should Tag all VLANS on those ports but:

1) VLAN 1 the default one does not seem to let me Tag it.

2) What other Ingress, Egress, LAG etc settings should I set on those ports.

We are in the process of setting up some Layer3 switches for our routing so this is becomming very critical that these switches can communicate with VLANS from other switches.

Thanks,

Roger

ThiasDude · Answer

Roger : Have you ever been able to solve this situation?

I'm having the exact same problem currently with a 2716, where I am unable to trunk 2 vlans between it and another different switch (3324, which is already trunked fine with another switch, a 5324))... I'm going nuts!

Matthias

ThiasDude · Answer

I managed to get two VLANs trunked to the 2724, but since none are VLAN 1, I had to do all the configuration with a laptop connected to a "dedicated" port which I had to leave in VLAN 1, and I can no longer remotely manage or monitor the switch.

The "managed" mode on these switches should really be regarded as what it really is : A simple extra, which one might get working (with luck and perseverence) in a limited way, after much trouble and without being able to achieve all that was wanted...

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HELP setting up 2724 and 2716 for spanning VLANs

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