Intermittent dataflow on LAN with HPUX servers

[inactive account]

Hi everybody and hope you had a good christmas.

Here is my Question:

We have several HP-UX 11.0 servers for development purpose which are connected on our LAN.
Periodically, they seem to block the flow of messages (in ou out) for as much as 60 seconds and then they are back.
What could be the problem?
I precise that they are neighbours of different LINUX, AIX 4.3 boxes which never show this behaviour.

thanks

Laurent

[Rajeev Shukla]

There could be multiple reasons and you'll have to take cases one a time.
There could be problem with the network card of any of the servers.
Or there could be some software running on eiver of the boxes like NNM, any snmp protocols whoch might be blocking the network.
It would be a good idea to make separate VLANS. Make production servers in one vlan, development servers on separate vlan and clients on a different vlan. Also if possible separate the linux server from the normal vlans. I suspect linux server more any any other for this coz, so move servers slowly.
Format the output of nettl using netfmt and see if it more than ususal packets.

Rajeev

[T G Manikandan]

Just do a lanadmin
then type 'lan'
then type 'display'

check for any collisions or errors.

Revert

[inactive account]

here are the measures:


LAN INTERFACE STATUS DISPLAY
Thu, Dec 26,2002 09:56:08

PPA Number = 0
Description = lan0 Hewlett-Packard 10/100 TX Full-Duplex Manual TT = 1500
Type (value) = ethernet-csmacd(6)
MTU Size = 1500
Speed = 100000000
Station Address = 0x306e1b6f95
Administration Status (value) = up(1)
Operation Status (value) = up(1)
Last Change = 5403
Inbound Octets = 255758652
Inbound Unicast Packets = 978939
Inbound Non-Unicast Packets = 89864
Inbound Discards = 1467
Inbound Errors = 2083
Inbound Unknown Protocols = 7
Outbound Octets = 569912164
Outbound Unicast Packets = 1284318
Outbound Non-Unicast Packets = 1467
Outbound Discards = 0
Outbound Errors = 0
Outbound Queue Length = 0
Specific = 655367

[inactive account]

I forgot the end!
here it is:

Ethernet-like Statistics Group

Index = 1
Alignment Errors = 963
FCS Errors = 2083
Single Collision Frames = 0
Multiple Collision Frames = 0
Deferred Transmissions = 0
Late Collisions = 0
Excessive Collisions = 0
Internal MAC Transmit Errors = 0
Carrier Sense Errors = 0
Frames Too Long = 0
Internal MAC Receive Errors = 0

[inactive account]

on another system I have:

LAN INTERFACE STATUS DISPLAY
Thu, Dec 26,2002 10:59:55

PPA Number = 0
Description = lan0 Hewlett-Packard 10/100 TX Half-Duplex TT = 1500
Type (value) = ethernet-csmacd(6)
MTU Size = 1500
Speed = 10000000
Station Address = 0x306e0c3b7d
Administration Status (value) = up(1)
Operation Status (value) = up(1)
Last Change = 665
Inbound Octets = 1379807624
Inbound Unicast Packets = 37679264
Inbound Non-Unicast Packets = 922772
Inbound Discards = 35868
Inbound Errors = 0
Inbound Unknown Protocols = 31283
Outbound Octets = 2703614737
Outbound Unicast Packets = 35480557
Outbound Non-Unicast Packets = 18919
Outbound Discards = 93722
Outbound Errors = 354
Outbound Queue Length = 0
Specific = 655367

Press to continue


Ethernet-like Statistics Group

Index = 1
Alignment Errors = 0
FCS Errors = 0
Single Collision Frames = 767399
Multiple Collision Frames = 123390
Deferred Transmissions = 452593
Late Collisions = 0
Excessive Collisions = 354
Internal MAC Transmit Errors = 0
Carrier Sense Errors = 0
Frames Too Long = 0
Internal MAC Receive Errors = 0

which shows a lot of collisions and deferred transmissions

any suggestions?

thanks by advance!

Laurent

[T G Manikandan]

The output clearly indicates that one system is running at

Speed=100000000(100MB)
and another machine
speed=10000000 (10Mb)
and also there is a //duplex mismatch//

Make sure that both the servers speak at same speed and same duplex settings so that the collisions and errors are avoided .
ALso make sure that you have the same speed and duplex settings on the switch also.

REvert with results once things are done.

[inactive account]

The two systems run on different LAN branches, one is running at 100 Mb and the other at 10 Mb.

How do I change from half-duplex to full-duplex?

Thank you!

Laurent

[Ravi_8]

Hi, Laurent

SAM-->Network and communications --> network interface card --> select lan0 (since you are using lan0) -->action -->modify
here make auoto negotiation ON and Duplex mode to FULLand then OK.

[T G Manikandan]

On the machine with 10MB and half duplex

Just do a

#anadmin -X 100FD lan0

[T G Manikandan]

Sorry it is

lanadmin


Also make sure to update the appropriate file of your card to keep it permanent

btlan hpbtlanconf
btlan0 hpeisabtconf
btlan1 hpbasetconf
btlan3 hpbase100conf Internal (core) LAN card
btlan4 hpgsc100conf
btlan5 hppci100conf "external" PCI card A5230A
btlan6 hpsppci100conf V-class PCI lan card
gelan hpgelanconf GigaBit card A4926A


REvert

[inactive account]

Sorry but I cna't change to 100Mb HD because:
1) it is connected on a 10 MB network
2) it refuses to go on Full Duplex whatever I use SAM or direct lanadmin command.
With lanadmin I get:

lanadmin -X 10FD lan0 0

WARNING: an incorrect setting could cause serious network problems!!!

btlan3: ERROR: Setting 10FD is unsupported
Valid types: 10HD, 10FD, 100HD, 100FD, AUTO_ON
root@hpisim:/>

[T G Manikandan]

For which machine you are trying to change the speed ?
What are the switch settings?
Revert

[Bill Hassell]

The big question is how the LAN card is connected to the network. Is it a simple hub or is it a switch that supports multiple speeds. The FCS and framing errors indicate big problems with the connection (100 Mbit and full duplex). 100FD means there can be no collisions since transmit and receive go on simultaneously. 10 Mbit is always half-duplex for virtually all systems.

If you are using a switch, connect to the switch and change that computer's port to turn off autonegotiation (probably the cause of the problem) and lock that port to 100FD. Now the FCS and framing errors should disappear and your LAN throughput should go up by 10-50x faster. Use lanadmin to zero the stats and compare the results. Autonegotiation will fail at certain cable lengths.