perfSONAR User Q&A and Other Discussion

["Manglos, Andrew P (173E)" <>]

Hello Doug,

 

This is what I find in my /etc/sysctl.conf file

 

net.ipv4.conf.all.arp_ignore=1

net.ipv4.conf.all.arp_announce=2

net.ipv4.conf.default.arp_filter=1

net.ipv4.conf.all.arp_filter=1

net.ipv4.conf.default.rp_filter = 2

net.ipv4.conf.all.rp_filter = 2

 

This is what appears when I type “sysctl –a | grep rp"

 

net.core.rps_sock_flow_entries = 0

net.ipv4.tcp_max_orphans = 262144

net.ipv4.tcp_orphan_retries = 0

net.ipv4.conf.all.rp_filter = 2

net.ipv4.conf.all.proxy_arp = 0

net.ipv4.conf.all.arp_filter = 1

net.ipv4.conf.all.arp_announce = 2

net.ipv4.conf.all.arp_ignore = 1

net.ipv4.conf.all.arp_accept = 0

net.ipv4.conf.all.arp_notify = 0

net.ipv4.conf.all.proxy_arp_pvlan = 0

net.ipv4.conf.default.rp_filter = 2

net.ipv4.conf.default.proxy_arp = 0

net.ipv4.conf.default.arp_filter = 1

net.ipv4.conf.default.arp_announce = 0

net.ipv4.conf.default.arp_ignore = 0

net.ipv4.conf.default.arp_accept = 0

net.ipv4.conf.default.arp_notify = 0

net.ipv4.conf.default.proxy_arp_pvlan = 0

net.ipv4.conf.lo.rp_filter = 2

net.ipv4.conf.lo.proxy_arp = 0

net.ipv4.conf.lo.arp_filter = 1

net.ipv4.conf.lo.arp_announce = 0

net.ipv4.conf.lo.arp_ignore = 0

net.ipv4.conf.lo.arp_accept = 0

net.ipv4.conf.lo.arp_notify = 0

net.ipv4.conf.lo.proxy_arp_pvlan = 0

net.ipv4.conf.eth0.rp_filter = 2

net.ipv4.conf.eth0.proxy_arp = 0

net.ipv4.conf.eth0.arp_filter = 1

net.ipv4.conf.eth0.arp_announce = 0

net.ipv4.conf.eth0.arp_ignore = 0

net.ipv4.conf.eth0.arp_accept = 0

net.ipv4.conf.eth0.arp_notify = 0

net.ipv4.conf.eth0.proxy_arp_pvlan = 0

net.ipv4.conf.eth1.rp_filter = 2

net.ipv4.conf.eth1.proxy_arp = 0

net.ipv4.conf.eth1.arp_filter = 1

net.ipv4.conf.eth1.arp_announce = 0

net.ipv4.conf.eth1.arp_ignore = 0

net.ipv4.conf.eth1.arp_accept = 0

net.ipv4.conf.eth1.arp_notify = 0

net.ipv4.conf.eth1.proxy_arp_pvlan = 0

net.ipv4.conf.wlan0.rp_filter = 2

net.ipv4.conf.wlan0.proxy_arp = 0

net.ipv4.conf.wlan0.arp_filter = 1

net.ipv4.conf.wlan0.arp_announce = 0

net.ipv4.conf.wlan0.arp_ignore = 0

net.ipv4.conf.wlan0.arp_accept = 0

net.ipv4.conf.wlan0.arp_notify = 0

net.ipv4.conf.wlan0.proxy_arp_pvlan = 0

 

Everything looks as expected except for net.ipv4.conf.all.arp_announce and net.ipv4.conf.all.arp_ignore (bold/italicized above). They seem to be set correctly for all but when it shows the specific interface it shows a different value. Is that expected or is this the issue that needs to be fixed?

 

Thanks once again for your help.

 

 

-Andrew Manglos

Network Engineer

Work#: 818-393-2419 (x32419)

Cell#: 626-710-2092

 

From: Wussler, Doug [mailto:]
Sent: Monday, April 25, 2016 7:59 AM
To: Manglos, Andrew P (173E) <>
Cc:
Subject: Re: [perfsonar-user] Dual NIC's on Same Subnet

 

Andrew -

 

All I did was follow the same instructions you already reference, http://docs.perfsonar.net/manage_dual_xface.html, and then add the parameters mentioned at http://z-issue.com/wp/linux-rhel-6-centos-6-two-nics-in-the-same-subnet-but-secondary-doesnt-ping/.  All I can suggest is that you double-check your changes to confirm they are permanently set.  One little typo is enough to mess it up.

 

use “sysctl –a | grep rp" to verify the 6 kernel parameters

and use “ip rule list” to verify your routing changes, as suggested in http://docs.perfsonar.net/manage_dual_xface.html

 

I’m sorry, I don’t have any other ideas.

 

Doug

 

 

From: "Manglos, Andrew P (173E)" <>
Date: Friday, April 22, 2016 at 6:28 PM
To: Default User Name <>, "" <>
Cc: "" <>
Subject: RE: [perfsonar-user] Dual NIC's on Same Subnet

 

Hello Doug,

 

Sorry for the late reply. I changed/added those settings and at first I was able to ping/ping from both interfaces. After a few seconds it stopped working. I restarted the box and it worked again for a few seconds but then stopped again and I can only ping out one interface.

 

 

-Andrew Manglos

Network Engineer

Work#: 818-393-2419 (x32419)

Cell#: 626-710-2092

 

From: Wussler, Doug []
Sent: Thursday, April 21, 2016 1:37 PM
To: Manglos, Andrew P (173E) <>;
Cc:
Subject: Re: [perfsonar-user] Dual NIC's on Same Subnet

 

I have it working.  If I recall, the document you refer to is missing a couple of settings:

 

net.ipv4.conf.default.rp_filter = 2

net.ipv4.conf.all.rp_filter = 2

 

You can find the full explanation here:

http://z-issue.com/wp/linux-rhel-6-centos-6-two-nics-in-the-same-subnet-but-secondary-doesnt-ping/

 

 

Doug Wussler

850.645.4201

Application Developer/Designer – Core Network Team

Information Technology Services

RK Shaw Building

644 W. Call Street

Tallahassee, FL  32304

 

 

From: <> on behalf of "Manglos, Andrew P (173E)" <>
Date: Thursday, April 21, 2016 at 4:28 PM
To: "" <>
Cc: "" <>
Subject: [perfsonar-user] Dual NIC's on Same Subnet

 

Hello,

 

I would like to setup a perfSonar node to have two interfaces on the same subnet (1 for throughput and 1 for latency). I checked on the perfSonar website and found the below link that says it is possible but it only went over how to configure two interfaces on separate networks. Currently, when I have both interfaces up and on the same subnet only 1 interface will respond to pings. If I shutdown the working interface, the non-working interface will start responding. Any help would be greatly appreciated.

 

 

http://docs.perfsonar.net/manage_dual_xface.html

 

 

-Andrew Manglos

Network Engineer

Work#: 818-393-2419 (x32419)

Cell#: 626-710-2092