Web and Unmanaged
cancel
Showing results for 
Search instead for 
Did you mean: 

1920 trunk to 1810 and 1820

ckvm
Occasional Visitor

1920 trunk to 1810 and 1820

Hello!

Does anyone have experience with this scenario? With this configuration, there is an intermittent network dropout throughout the day.

Network Diagram

Any help would be very much appreciated. Thank you.

Regards,
Kevin

6 REPLIES
parnassus
Honored Contributor

Re: 1920 trunk to 1810 and 1820

It's not so special (a Switch in a central position with two uplinks - respectively via two 2 ports BAGGs - to two other Switches).

Can you detail the "intermittent network dropout throughout the day"? what happens?

What 1920's Log (and BAGGs status) reports exactly?

Are you using LACP or Non-Protocol aggregations methods on BAGG1 and BAGG2 against 1810 and 1820?

Are the uplinks stable?

How your clients/servers are distributed on that network topology? how many of them you have?
ckvm
Occasional Visitor

Re: 1920 trunk to 1810 and 1820

 

Hello,

Can you detail the "intermittent network dropout throughout the day"? what happens?
1.  I tested copying large files between VLANs, it didn't even start, just hung there, I was also running ping -t from a machine connected to HP 1820-24G to a server connected to HP 1810-24G and it timed out. I also ran another ping -t to the HP 1810-24G, also timed out. When I stop the file transfer, all pings goes back to normal. 
2. Connection from clients to server are intermittent, our desktop applications that points to our servers disconnects intermittently.

What 1920's Log (and BAGGs status) reports exactly?
The logs from time to time will show stp network topology change, they come in group, say like 5-6 of them in one time, unfortunately I do not have the exact log message anymore as the logs were cleared.

Are you using LACP or Non-Protocol aggregations methods on BAGG1 and BAGG2 against 1810 and 1820?
Yes.

Are the uplinks stable?
Yes.

How your clients/servers are distributed on that network topology? how many of them you have?
Clients are residing in VLAN 2, 3, 5 while servers are all in VLAN 1.

Vince-Whirlwind
Honored Contributor

Re: 1920 trunk to 1810 and 1820

Reduce the STP priority on the middle switch.

Check switchport stats and switch logs. and study both carefully.

16again
Respected Contributor

Re: 1920 trunk to 1810 and 1820

Vince, afaik the 1810 hasn't got spanning tree

Vince-Whirlwind
Honored Contributor

Re: 1920 trunk to 1810 and 1820

You're right.

So on the 1920 you should block BPDUs out BAGG2, and on the 1810 you should disable loop protection on Trunk1.

And the 1920 should have its STP priority lowered.

16again
Respected Contributor

Re: 1920 trunk to 1810 and 1820

Further digging from memory:  Was the 1810 the switch which couldn't handle VLANs properly?  
The extra tag costs 4 extra bytes, so you had to lower MTU on NICs to 1496 to make packets fit