AW: Arp Cache issue

Wed Jul 13 14:34:10 UTC 2011

Hello,

why you perpetually send e-mail to me ??

Please clear it and remedy this! 

Thank you and kind regards,

Christoph Walther

T-Systems International GmbH
Computing Services & Solutions (CSS)
Open Systems Engineering (VSnfD-DPOT)
Mergenthalerallee 42, 65760 Eschborn
Germany, Europe
+49 6196 961 74555 (Phone)
+49 6196 961 12455 (Fax)
+49 151 117 13194   (Mobile)
E-mail:    christoph.walther at t-systems.com
Internet: http://www.t-systems.com

T-Systems International GmbH
Supervisory Board: René Obermann (Chairman)
Board of Management: Reinhard Clemens (Chairman), Dr. Ferri Abolhassan, Ulrich Meister, Georg Pepping, Hagen Rickmann, Dietmar Wendt, Klaus Werner
Commercial register: Amtsgericht Frankfurt am Main HRB 55933
Registered office: Frankfurt am Main
WEEE-Reg.-No. DE87523644

Notice: This transmittal and/or attachments may be privileged or confidential. It is intended solely for the addressee named above. Any review, dissemination, or copying is strictly prohibited. 
If you received this transmittal in error, please notify us immediately by reply and immediately delete this message and all its attachments. Thank you.

Big changes start small - conserve resources by not printing every e-mail.

-----Ursprüngliche Nachricht-----
Von: redhat-list-bounces at redhat.com [mailto:redhat-list-bounces at redhat.com] Im Auftrag von Richardson, Joshua A.
Gesendet: Mittwoch, 13. Juli 2011 16:18
An: General Red Hat Linux discussion list
Betreff: RE: Arp Cache issue

Can you post your /etc/sysctl.conf file?  Maybe the answer resides in your arp cache size limits and garbage collection frequency?

Thanks!

Josh Richardson
General Dynamics AIS

-----Original Message-----
From: redhat-list-bounces at redhat.com [mailto:redhat-list-bounces at redhat.com] On Behalf Of brian irvin
Sent: Wednesday, July 13, 2011 9:34 AM
To: General Red Hat Linux discussion list
Subject: Re: Arp Cache issue

We are using bnx2 driver. We are getting outages when arp table fills up and unless we flush the table, network connectivity is an issue. 

more ifcfg-bond0
DEVICE=bond0
BONDING_OPTS="mode=1 miimon=500 primary=eth4"  

Thanks

Brian

--- On Tue, 7/12/11, Georgios Magklaras <georgios at biotek.uio.no> wrote:

> From: Georgios Magklaras <georgios at biotek.uio.no>
> Subject: Re: Arp Cache issue
> To: "General Red Hat Linux discussion list" <redhat-list at redhat.com>
> Date: Tuesday, July 12, 2011, 9:41 PM
> On 07/12/2011 09:46 PM, brian irvin
> wrote:
> > We have a RHEL 5 box which requires frequent flushing
> of arp cache to stay up and running and not create network 
> bottlenecks. Anyone have these issues? we have quite a few servers and 
> have never faced an issue before this one. I thought it might have to 
> do with the switch but the network folks say the switch is clear. Any 
> thoughts??
> > 
> > cat /proc/net/bonding/bond0
> > Ethernet Channel Bonding Driver: v3.4.0 (October 7,
> 2008)
> > 
> > Bonding Mode: fault-tolerance (active-backup) Primary Slave: eth4 
> > Currently Active Slave: eth4 MII Status: up MII Polling Interval 
> > (ms): 500 Up Delay (ms): 0 Down Delay (ms): 0
> > 
> > Slave Interface: eth0
> > MII Status: up
> > Link Failure Count: 0
> > Permanent HW addr: 00:37:c9:38:e3:3b
> > 
> > Slave Interface: eth4
> > MII Status: up
> > Link Failure Count: 0
> > Permanent HW addr: 00:11:17:4c:ee:22
> > 
> > 
> > Thanks
> > 
> > Brian.
> > 
> 
> Can you clarify a bit the staying up and running/bottleneck issue? 
> What happens if you do not flush the ARP table in terms of what you 
> see in the system and what do you see on the LAN side for the system? 
> Also which Ethernet driver module you use in the system?
> 
> I have seen issues with IP aliasing (not HA bonding) on very busy 
> LANs, but long time ago, not on recent 5 releases.
> As far as I know, unless you use a load balancing mode bonding, the 
> netwrk switch should not be tweaked.
> 
> 
> GM
> 
> -- -- George Magklaras PhD
> RHCE no: 805008309135525
> 
> Senior Systems Engineer/IT Manager
> Biotek Center, University of Oslo
> EMBnet TMPC Chair
> 
> http://folk.uio.no/georgios
> 
> Tel: +47 22840535
> 
> -- redhat-list mailing list
> unsubscribe mailto:redhat-list-request at redhat.com?subject=unsubscribe
> https://www.redhat.com/mailman/listinfo/redhat-list
> 

--
redhat-list mailing list
unsubscribe mailto:redhat-list-request at redhat.com?subject=unsubscribe
https://www.redhat.com/mailman/listinfo/redhat-list

--
redhat-list mailing list
unsubscribe mailto:redhat-list-request at redhat.com?subject=unsubscribe
https://www.redhat.com/mailman/listinfo/redhat-list