Configure a 3Com switch 4800G

[ruby_1]

Hi,

I'm getting some difficulty to configure a 3Com switch 4800G.

This one is plugged in on 3Com switch 4228G with a category 5e patch cable.  The link light must become green for both ports except it is not the case.


The devices support autonegotiation and 10BASE-T/100BASE-TX transmissions.


The supplied RJ-45-to-DB-9 adapter cable is used to connect the console port PC. Using Hyperterminal, I succeed to configure an IP address and the netmask.

The "display vlan" display the Vlan configuration. All ports are assigned to VLAN 1  by default

Side 4228G, the port is configured to transmit untagged  frames on Vlan1 and tagged frames on Vlan2.

If I examine the MAC address table of 3Com switch 4228G, I don't find the MAC address of 3Com switch 4800G.

Thanks in advance for any help

This message was edited by ruby on 8-21-10 @ 6:43 AM

[chrisuk]

Have you set the interfaces on both switches which connect to each other to trunk ports and allowed vlans 1 and 2?

eg:

interface Ethernet1/0/1


 poe enable


 stp edged-port enable


 port link-type trunk


 port trunk permit vlan 1 to 2


 broadcast-suppression pps 3000


 undo jumboframe enable


 lacp enable


 port link-aggregation group 1


 apply qos-profile default

You may also want to look into creating a link aggregation group to increase the bandwidth over the link and add fault tolerance.

This message was edited by chrisuk on 8-21-10 @ 11:31 AM

[ruby_1]

Thx so much.





To resume :





1) I select the mode system view





system-view





2) I select Ethernet port view





interface Ethernet1/0/1 





3) I change a port’s link type from access to trunk because the link type of a port is access by default.





4) I assign the current port to VLANs 1 to 2





port trunk permit vlan 1 to 2








Some questions (newbie) :





- I have set the interfaces on both switches. Isn't it ?





- How can I configure the link type for a specific port (17 for example) ?





interface Ethernet 1/0/17 (?)


I don't understand the interface number argument.





1 ?


0 ?





- Why do I have to create a trunk ? I have some switches behind the 3Com switch 4228G. The port for interconnection is untagged on Vlan1 and tagged on Vlan2.

[ruby_1]

--> Considering un access port packet processing (in reference to 3com Swicth 5500 Family configuration Guide):





1) By default, all Ethernet ports belong to Vlan 1, the port 17 (side 4800G) receive/match an untagged packet from 3Com switch 4228G (because the selected port is configured to transmit untagged packets on Vlan1 and tagged packets on Vlan2). It add the default Vlan tag to the packet.


For an outgoing packet, it strip the tag from the packet and send the packet. OK.





Why it does not work and the link light doesn't become green for both ports ?





Do I have to create a Vlan 2 and assign the specified port (17) to the Vlan2 ?





vlan 2


port Ethernet 1/0/17





How to specify a tagged port ?





2) If the port 17 (side 4800G) receive/match a tagged packet (Vlan id 2) from 3Com switch 4228G. The Vlan id is not the default Vlan and the packet will be discard.





It is not what I want !





--> Using 3com series 4200 switches, the ports for interconnection are untagged on Vlan1 and tagged on Vlan2 and everything is fine !





Any help will be greadly apprecied. Thanks in advance.

[ruby_1]

Two problems solved :





1) Port on 3Com switch 4800G was configured for full-duplex while trunk port on 3Com switch 4228G was defaulted to half-duplex.


2) Side 3Com switch 4800G, I had to configure the trunk port as active link (undo shutdown command)