Comware Based
1757186 Members
2475 Online
108858 Solutions
New Discussion

Re: LACP on 3Com 3CDSG8

 
theonek
Occasional Contributor

LACP on 3Com 3CDSG8

Hi! I recently bought one of these switches. So the idea was to use a 2Gb lan with this link aggregation supported by this model switch. I have a 3PCs with dual lan capability. Two of them are with Realtek 8111DL lan chips which supports link aggregation by teaming. The last one is nforce network controllers with the same teaming functionality. But when I connect all PCs to the switch with runing LACP protocol on switch there is no lan, only connected to 2Gb and that is. No browse network sharings or internet. If someone can tell me is this scenario possible to connect every of PCs with 2Gb link aggregation on this switch and if it is possible how to configure the switch to work with these 3 PCs in 2Gb link aggregation or is it better to use only trunking? Thanks!

6 REPLIES 6
Fred_Mancen_1
Super Advisor

Re: LACP on 3Com 3CDSG8

Hi.



Usually is necessary too create a link-aggregation group manually; enable LACP on the switch ports is not enough.

Try this:



Global configuration:



link-aggregation group mode manual

link-aggregation group description



Interface settings:



port link-aggregation group



To display LAG status:



display link-aggregation verbose



The link-type on the ports can be access or hybrid ports; trunk ports are not recommended on this specific case. The grouped ports need to have exactly the same configuration.



HTH

Regards,
Fred Mancen
theonek
Occasional Contributor

Re: LACP on 3Com 3CDSG8

Thanks for answer, but I forgot to mention that I'm very new to this specific configurations of networks. So it is nice to see an idea how to configure the switch but I don't know where and how to do this specific commands. Is it through a console and have I connect the switch to PC throgh a console cable(in this switch case lan to RS-232)? If someone could explain further step by step needed operations? Thanks!

Fred_Mancen_1
Super Advisor

Re: LACP on 3Com 3CDSG8

If you are a newbie, I think it's better to access the switch through web console (browser interface) and read the configuration guide. Depending on its model, the switch could have several options to setup an aggregation link.



HTH

Regards,
Fred Mancen
theonek
Occasional Contributor

Re: LACP on 3Com 3CDSG8

Well the point is that there is no manual configuration on a LAG on the switch. The model is Office Connect 3CDSG8 which seems to be some kind of a baseline for supporting these advanced configurations. And I need help really how to manual configure LAG groups to use This LACP protocol propertly. And the thing is if I must use every PC on a different group so how it is done? And my question was for a working scenario of my network.



Fred_Mancen_1
Super Advisor

Re: LACP on 3Com 3CDSG8

I was reading the datasheet, and this switch does not support LACP to hosts, only for trunk ports.It can support up 4 trunks, with 8 ports grouped (a pair of ports per trunk).



HTH.



This message was edited by Fred_Mancen on 11-18-09 @ 6:56 AM
Regards,
Fred Mancen
msavazzi
Occasional Collector

Re: LACP on 3Com 3CDSG8

Where did you found that information?

 

from the manual:

This page allows you to configure LACP for each port. The switch supports both static trunking and dynamic Link Aggregation Control Protocol (LACP). LACP configured ports can automatically negotiate a trunked link with LACP-configured ports on another device. You can configure any number of ports on the switch as LACP, as long as they are not already configured as part of a static trunk. If ports on another device are also configured as LACP, the switch and the other device will negotiate a trunk link between them. If an LACP trunk consists of more than eight ports, all other ports will be placed in a standby mode. Should one link in the trunk fail, one of the standby ports will automatically be activated to replace it. The LACP Table has one row for each port and three columns.

 

There is no mention on restrictions to hosts.

 

Also LACP works towards my NAS but not towards my server (two Realtek NIC)° even if I have the teaming created in LACP mode.

 

 

In addition to that the behaviour is very strange as if I go on the router and continue to click refresh every now and then the two ports team then they disconnect.

When they team the "seconds since last chage" is a massive number like 220923 that makes no sense.

 

Any help?

did anyone sorted this out?