No DHCP on pfSense VLAN with Cisco Smart Switch

[johnpoz]

@pete35 all of that has already been done. Sniff on port going to pfsense no vlan tags - which has nothing to do with pfense

[pete35]

@johnpoz
we are using a lot of these switches and i never saw such problems. There are other problems with this switches but not within those basic vlan stuff. As these switches have a lifetime warranty from cisco, maybe a return and exchange will solve this issue. Otherwise im out of ideas what is wrong here.

[Cannondale]

I plugged in a Linux workstation into switch port 20, which was a normal lan port.
Got an IP from pfSense as expected.
Configured switch port 20 as a vlan using the cli. Note: port 20 was not previously configured as a vlan.

Output below of:
show vlan
sho run int
show interfaces switchport

Note: Switch port 1 is the pfSense Trunk port.

Roth-SG250-50P-1(config-if)#do show vlan
Created by: D-Default, S-Static, G-GVRP, R-Radius Assigned VLAN, V-Voice VLAN

Vlan       Name           Tagged Ports      UnTagged Ports      Created by    
---- ----------------- ------------------ ------------------ ---------------- 
 1           1                            gi2-19,gi21-23,           DV        
                                          gi25-50,Po1-4                       
 10      testvl10             gi1                gi24               S         
 20      testvl20             gi1                gi20               S         


Roth-SG250-50P-1#sho run int gi1
interface GigabitEthernet1
 switchport mode trunk
 switchport access vlan 10
 switchport trunk allowed vlan 10,20
!

Roth-SG250-50P-1#sho run int gi20
interface GigabitEthernet20
 switchport access vlan 20
!


Roth-SG250-50P-1(config-if)#do show interfaces switchport ge1
Name: gi1
Switchport: enable
Administrative Mode: trunk
Operational Mode: up
Access Mode VLAN: 10
Trunking Native Mode VLAN: 1 (Inactive)
Trunking VLANs: 10,20
General PVID: 1
General VLANs: none
General Egress Tagged VLANs: none
General Forbidden VLANs: none
General Ingress Filtering: enabled
General Acceptable Frame Type: all
General GVRP status: disabled
Customer Mode VLAN: none


Roth-SG250-50P-1(config-if)#do show interfaces switchport ge20
Name: gi20
Switchport: enable
Administrative Mode: access
Operational Mode: down
Access Mode VLAN: 20
Trunking Native Mode VLAN: 1
Trunking VLANs: 1,10,20
                        2-9,11-19,21-4094 (Inactive)
General PVID: 1
General VLANs: none
General Egress Tagged VLANs: none
General Forbidden VLANs: none
General Ingress Filtering: enabled
General Acceptable Frame Type: all
General GVRP status: disabled
Customer Mode VLAN: none


Roth-SG250-50P-1(config-if)#do show interfaces switchport ge24
Name: gi24
Switchport: enable
Administrative Mode: access
Operational Mode: up
Access Mode VLAN: 10
Trunking Native Mode VLAN: 1
Trunking VLANs: 1,10,20
                        2-9,11-19,21-4094 (Inactive)
General PVID: 1
General VLANs: none
General Egress Tagged VLANs: none
General Forbidden VLANs: none
General Ingress Filtering: enabled
General Acceptable Frame Type: all
General GVRP status: disabled
Customer Mode VLAN: none

I ran tcpdump -i igb1 -e on the pfSense server while plugging in the Linux workstation into port 20.
Searched the sniffer output for "vlan" and did not find that string.

[pete35]

@cannondale

Try to configure another port to vlan 10 from/with the GUI. Save the config and reboot the switch and test afterwards. I just checked one of my switches and it works straightforward.

[Cannondale]

@pete35 said in No DHCP on pfSense VLAN with Cisco Smart Switch:

Try to configure another port to vlan 10 from/with the GUI. Save the config and reboot the switch and test afterwards.

Thanks for the suggestion pete35!
Configured switch port 23 to be a member of vlan 10 via GUI.
copied running-config to startup-config

Show output below.

Roth-SG250-50P-1#show vlan
Created by: D-Default, S-Static, G-GVRP, R-Radius Assigned VLAN, V-Voice VLAN

Vlan       Name           Tagged Ports      UnTagged Ports      Created by    
---- ----------------- ------------------ ------------------ ---------------- 
 1           1                            gi2-19,gi21-22,           DV        
                                          gi25-50,Po1-4                       
 10      testvl10             gi1              gi23-24              S         
 20      testvl20             gi1                gi20               S         

Roth-SG250-50P-1#sho run int gi1
interface GigabitEthernet1
 switchport mode trunk
 switchport access vlan 10
 switchport trunk allowed vlan 10,20
!
Roth-SG250-50P-1#sho run int gi23
interface GigabitEthernet23
 switchport access vlan 10

Ran tcpdump -i igb1 -e on the pfSense box while plugging in the Linux workstation into port 23. Searched the sniffer output for "vlan" and did not find that string.

Note: was not able to bounce the switch before the test as several users are using the system.
Can try that later today if it would help.

[johnpoz]

@cannondale said in No DHCP on pfSense VLAN with Cisco Smart Switch:

was not able to bounce the switch before

There is no reason you should have to bounce the switch, the only time you should ever have to reboot a switch is if you are updating its firmware.

Well @mvikman shows his output as showing that vlan 1 as native for ingress and says its working.. Which isn't what the output would express if you ask me.

But yours isn't

My sg300 correctly shows that native ingress on whatever access vlan I put on a port.. See my example output where I change the port 28 to different vlan and then back, etc..

Maybe the sg250 is just crap when it comes to what the cli shows - but then why isnt this working?

For a last hope go to general mode and specifically set the native vlan and the vlan your on..

But sorry if your not seeing tagged coming into pfsense where you have a vlan setup - its never going to work.. That is for sure..

[Cannondale]

johnpoz, thanks for continuing to hang in there!
The Interface Settings page in the GUI only shows two options for a port. Access and Trunk.

But the Port VLAN Membership page in the GUI shows Access, Trunk, General and Customer.

My question is can I change the port access mode to General in the cli if the General option in not available in the GUI? If so would it appear as General on the Port VLAN Membership page?

[Cannondale]

Update:

Tried configuring port 20 (VLAN20) via cli to general mode.

Roth-SG250-50P-1(config)#do sho run int ge20
interface GigabitEthernet20
 switchport mode general
 switchport general allowed vlan add 20 untagged
 switchport access vlan 20
 switchport general pvid 20
!

Roth-SG250-50P-1(config-if)#do sho run int ge1
interface GigabitEthernet1
 switchport mode trunk
 switchport trunk allowed vlan 10,20
!

Looked at the GUI Port VLAN Membership page, which looked ok to me.
Couldn't upload the screenshot here do to error:parse-error.
Here is the text version:

F - Forbidden member	T - Tagged member	U - Untagged member	I - Inactive VLAN	P - PVID
Interface	Mode	Administrative VLANs	Operational VLANs
GE1	        Trunk	1UI, 10T, 20T	                10T, 20T	
GE20	        General	20U, 20P	                20U

Ran tcpdump -i igb1 -e on the pfSense box while plugging in the Linux workstation into port 20. Searched the sniffer output for "vlan" and did not find that string.

OMG!

[mvikman]

Just a thought... the CBS-series GUI has a dropdown menu on the top right that switches between Basic and Advanced views, the Basic hides some stuff on the menus. Does the SG250 have that?

[pete35]

@Cannondale I did a quick configuration on a local CBS350 Switch with a tagged port from a pfsense to that switch similar the configuration you have. Requesting a DHCP address from a workstation on an acces port and dumping the traffic with tcpdump on the pfsense. Tcpdump doesn't show up any VLAN Information with tcpdump -i ix0 -e - but opening the dumpfile with wireshark shows DHCP Request and DHCP Ack to that port and to an Access port on that switch which works without any issues. Maybe you should search for DHCP in your dumpfile and not for vlan ?

Doing a PacketCapture on the pfsense also doesn't show up (with Wireshark) any VLAN information, but the DHCP Request and Ack Sequence.

It is not common to see Vlan tags on packet capture or tcpdump files, you need to configure the adapter for that. It looks like pfsense is not configured to show vlan tags on the interfaces for capturing.

Im assuming that your switch doing its job correctly.

TESTSWITCH#sh vlan
Created by: D-Default, S-Static, G-GVRP, R-Radius Assigned VLAN, V-Voice VLAN
Vlan Name Tagged Ports UnTagged Ports Created by

---

1 1 gi1/0/5, D
101 TEST1 gi1/0/5 gi1/0/6 S

TESTSWITCH#sh run interface gi 1/0/5
interface GigabitEthernet1/0/5
switchport mode trunk
switchport trunk allowed vlan 1,101
!
TESTSWITCH#sh run interface gi 1/0/6
interface GigabitEthernet1/0/6
switchport access vlan 101

[johnpoz]

@pete35 said in No DHCP on pfSense VLAN with Cisco Smart Switch:

Tcpdump doesn't show up any VLAN Information with tcpdump -i ix0 -e

And how is that - if your traffic is not tagged.. ?

It is not common to see Vlan tags on packet capture or tcpdump files

It is when you use -e

-e
    Print the link-level header on each dump line. This can be used, for example, to print MAC layer addresses for protocols such as Ethernet and IEEE 802.11.

[pete35]

@johnpoz

Showing up VLAN tags may depend on the pfsense type/version/device driver and the nic. At least within my configuration it doesnt show up any VLAN Tags. Lets check cannondales dump file again.

[johnpoz]

@pete35 said in No DHCP on pfSense VLAN with Cisco Smart Switch:

type/version/device driver and the nic

Possible.. But if it was working and sending the tags, why is his dhcp server not seeing the discover?

For it to work, the tags have to be there - so why wouldn't basic function of tcpdump not show them?

He is using igb interfaces - same as me. Maybe there is something with your ix interfaces, but have been using tcpdump for years.. I have never seen such an issue on all kinds of different hardware and OSes - and it for sure has worked on freebsd and pfsense going back as far as I can remember.

edit: Just ordered a sg250-08HP off ebay.. Going to play with one of these myself.. This can not be this difficult ;) Says should be here

Estimated delivery:
Sat, May 27 - Tue, May 30

Hoping for the 27th ;)

[Cannondale]

@mvikman
This is what my menu looks like:

[pete35]

@johnpoz
i cant imaging how this switch shouldnt do vlan tagging correctly. If its defect it wouldnt do anything. There are thousand of SGXXX switches out there, googleing for vlan tagging problems doesnt give any problems at all.

for the tcpdump vlan story: you see the vlan tags if running tcpdump with "-v". With "-w" it goes to a file which can be open with wireshark, vlan tags are not shown there by default.

[johnpoz]

@pete35 its quite possible he is looking at his output from tcpdump wrong? But I was quite clear on how to do it and showed examples.. Its a simple std output to the screen.

I am with you - there are 1000's or even 10s or 100s of thousands of these out there - if there was some issue with vlans you would think it would be easy enough to find people complaining.

I will have one to play with here in a few days ;) As long as it works - it will allow me to get rid of an injector using for my flex HD unifi AP have sitting on my floor in my computer room..

Its an open box off ebay - so you never know. But says fully operational just missing couple of the rubber feet on the bottom ;)

[pete35]

@johnpoz

I would really like to know the issue here. CBS350 or Catalyst 1000 is the better modern choice for this switches. SG250 is really old in terms of Cisco switches. Most of the models arent supported anymore by new firmware versions. Vlans are are working for pfsense and also for this Cisco switch. So there must be a issue between them or on layer 8 maybe.

[Cannondale]

Thanks for your efforts pete35! Very interesting information.
Not familiar with wireshark. Will install it and see what I can find.

I did check the pfSense DHCP log for DHCPREQUEST on the vlan20 IP but don't see anything. Just the entry for "Listening on BPF/igb1"

[pete35]

@johnpoz @Cannondale

pls reboot that switch:

[johnpoz]

@pete35 said in No DHCP on pfSense VLAN with Cisco Smart Switch:

anymore by new firmware versions

The sg250 seems to have gotten a firmware release quite recent.

My own sg300 hasn't had one since 18-Jun-2020

Pretty sure he has rebooted - since I know he changed firmwares at one point, etc.