How to use SG-300 Combo ports for loopback testing

[mlampell1]

Hi,

I've got an SG300-10P switch and am trying to use it to create a testing environment for a Fiber Test set. What I would like to do is get two hosts, A & B, plugged into ports 1 and 3 on the switch, to talk to each other, but forcing the traffic to be routed through the two Combo ports 9 & 10. Please see the attached diagram.

I've attempted to configure two VLAN's, 10 and 20. Vlan 10 is used for traffic between Ports 1 and 9, Vlan 20 is used for traffic between Ports 3 and 10.

I don't really care whether the traffic is tagged or untagged as it passes between ports 9 and 10.

I've tried various combinations of tagged/untagged ports, PVID's, etc. As a first test I've bypassed the Fiber Test set and simply created a direct connection between ports 9 and 10.  I am unable to get the traffic from Host A to Host B to get routed through ports 9 and 10 (I ping each host from the other and get no response).

Any ideas for how to achieve this?

Thanks,

Maurice Lampell

[David Hornstein]

Hi Maurice,

I am a bit perplexed.  Your diagram is pretty darn good by the way.  I have copied it below.

Is the ports 9 and 10 unntagged for the appropriate VLANs, that's what the diagram indicates?

Is VLAN1  excluded on both ports 9 and 10 ?

It seems to me that both VLAN10 and VLAN20 are transmitting untagged frames to the" fiber test equipment". Therefore as far as the fiber test equipment is concerned it has to assume that HOST A and HOST B are in the same IP network.

But,  for Host A and Host B to commucate with eachother, I would have to think that they would have to be in the same IP network, is that the case ?

Also; MiniGBIC interface is a combination port, shared with one other RJ-45 interface. When the MiniGBIC is active, the adjacent RJ-45 port is disabled.

dave

[mlampell1]

David,

Thanks for responding.

Host A and B are on the same subnet (e.g. 192.168.2.2 and 192.128.2.4). The VLAN's are meant to be an artifact to prevent the two hosts from talking directly to each other between ports 1 & 3.

I've tried this test with a fiber between the two mini-GBIC's, and I've also switched that out for an ethernet cable between the standard ethernet connectors on ports 9 & 10.

Host A and B are going to send untagged frames. The frames will get tagged upon entering the switch. It doesn't matter to me whether the frames between ports 9 and 10 are tagged or untagged, as long as Host A and B are able to talk to each other.

I have VLAN1 from ports 1,3,9 and 10.

Here is my Port VLAN membership:

g1, General, 10, 10U

g3, General, 20, 20U

g9, General, 20, 10U,20U (I tried setting the PVID to 10, but it reverts to 20)

g10, General, 20, 10U,20U

I'm wondering if either my fiber or ethernet cables need to be crossover cables...

Thanks,

Maurice

[David Hornstein]

Hi

Make sure you have the new 1.1 firmware on your switch.  This new firmware also gives you a supported CLI interface as well.

What  about trying the following VLAN configuration.

It will be easier during the firmware  upgrade, resetting the unit to factory defaults.

This is good as then it makes it easier to try the following VLAN configuration.

Ports 1 and 9   VLAN Interface set to Access mode . untagged vlan 10

ports 3 and 10   VLAN Interface set to Access mode,  untagged vlan 20

Yep fiber has to be crossed over transmit from one SFP going to RX or the other SFP .

Copper ports are OK as  they have auto-MDI-MDIX.

regards Dave

[mlampell1]

David,

Many thanks for the follow up.

I tried the configuration you suggested, using an ethernet cable between 9

and 10, but I could not get my ping to go from Host A to Host B.

Here is my Port Vlan membership:

g1, Access, 10, 10U

g3, Access, 20, 20U

g9, Access, 10, 10U

g10, Access, 20, 20U

Any chance you could try this simple test on your end?

Thanks!

Maurice

On Tue, Sep 6, 2011 at 12:43 PM, dhornste <

[David Hornstein]

Hi Maurice,

Here is my config which did work .

The SG300 is sometimes too smart for it's own good.

It has all sorts of discovery protocols and Spanning tree enabled by default, stuff you wouldn't see in a dumber switch, so congratulations for your good purchase in gettting a really smart managed switch.

I think the problem is the  switch saw Spanning tree BPDU coming back in and assumed a loop.

ok here is a working configuration from my SG300-10P  running 1.1.0.72.. pinging worked perfectly using SM SFP's in port 9 and 10  and SM crossed over fiber.

switch38cbaf#sh ver

SW version    1.1.0.72 ( date  15-Jun-2011 time  16:43:49 )

Boot version    1.0.0.4 ( date  08-Apr-2010 time  16:37:57 )

HW version    V01

switch38cbaf#show run

no cdp run

no spanning-tree

interface range gi9-10

spanning-tree link-type point-to-point

exit

vlan database

vlan 10,20

exit

voice vlan oui-table add 0001e3 Siemens_AG_phone________

voice vlan oui-table add 00036b Cisco_phone_____________

voice vlan oui-table add 00096e Avaya___________________

voice vlan oui-table add 000fe2 H3C_Aolynk______________

voice vlan oui-table add 0060b9 Philips_and_NEC_AG_phone

voice vlan oui-table add 00d01e Pingtel_phone___________

voice vlan oui-table add 00e075 Polycom/Veritel_phone___

voice vlan oui-table add 00e0bb 3Com_phone______________

no lldp run

hostname SG300-10

no snmp-server server

interface gigabitethernet1

switchport mode access

switchport access vlan 10

exit

interface gigabitethernet2

switchport mode access

exit

interface gigabitethernet3

switchport mode access

switchport access vlan 20

exit

interface gigabitethernet4

switchport mode access

exit

interface gigabitethernet5

switchport mode access

exit

interface gigabitethernet6

switchport mode access

exit

interface gigabitethernet7

switchport mode access

exit

interface gigabitethernet8

switchport mode access

exit

interface gigabitethernet9

switchport mode access

switchport access vlan 10

exit

interface gigabitethernet10

switchport mode access

switchport access vlan 20

exit

interface vlan 10

name ten

exit

interface vlan 20

name twenty

exit

switch38cbaf#sh mac address-table

Aging time is 300 sec

  Vlan        Mac Address         Port       Type

-------- --------------------- ---------- ----------

   1       f4:ac:c1:38:cb:af       0         self

   10      00:1a:6b:3c:ea:c1      gi1      dynamic

   10      f0:de:f1:03:c0:d4      gi9      dynamic

   20      00:1a:6b:3c:ea:c1      gi10     dynamic

   20      f0:de:f1:03:c0:d4      gi3      dynamic

switch38cbaf#

switch38cbaf(config)#do sh cdp

Global CDP information:

        CDP is globally disabled

        CDP log duplex mismatch is globally enabled

        CDP log voice VLAN mismatch is globally enabled

        CDP log native VLAN mismatch is globally enabled

        Mandatory TLVs validation is disabled

        Sending CDPv2 advertisements is enabled

        Sending Appliance TLV is enabled

        Device ID format is MAC Address

        Sending CDP packets every 60 seconds

        Sending a holdtime value of 180 seconds

        CDP packets handling mode is bridging

switch38cbaf(config)#

switch38cbaf(config)#do show spann

Spanning tree disabled (BPDU flooding) mode RSTP

Default port cost method:  long

[mlampell1]

David:

Thanks again for the time you took to look into this.

I disabled spanning tree protocol via the GUI and now I'm able to ping

across the twisted pair fibers.

Strangely, I can only ping in one direction (host a to host b, regardless of

whether hosts a/b are plugged into ports 1/3 or 3/1). I'm wondering if I

have an outgoing firewall turned on on host b...

In any case, it looks like you are showing me the CLI for the Cisco

SG300-10P. Is access to the CLI a standard part of the product?

If so, how is it done? Also if so, does the switch remain consistent between

the CLI and the GUI?

Thanks again!

Maurice

On Tue, Sep 6, 2011 at 2:28 PM, dhornste <

[David Hornstein · Accepted solution]

Hi Maurice,

I did suggest to make sure you are at the current version of firmware 1.1.1.8.

The current version of firmware has a supported CLI.

This CLI  running configuration is reflected in the GUI and conversely, changes made to the GUI are reflected immediately in the CLI.

Please check the administration guide as to how to upgrade the firmware.

regards Dave