Re: [CentOS] Neighbour table overflow
no. he can subnet it Typically ISP can assign /20. but client can subnet it two networks /22 /22 or 16 networks /24 Thank you John R Pierce [EMAIL PROTECTED] wrote: chloe K wrote: you have the network /20 so that you got this neigbour overlfow you should subnet it no, no, NO. his eth1 connection is from his ISP. He /has/ to use the supplied netmask, he can't reconfigure their network segment. now, why is ARP table is overflowing is another issue entirely. Thomas, can you try this? Do arp -an | grep 65.188.0.1 and pick out the MAC address of your gateway router, this will look something like... ? (65.188.0.1) at 00:17:CB:4F:97:81 [ether] on eth1 So, the MAC address above is 00:17:CB:4F:97:81 ... yours definitely will be different now, # tcpdump -i eth1 -n ip host 65.188.xxx.xxx and not ether host 00:17:CB:4F:97:81 (replacing that with your gateway router's MAC address as determined from that ARP command, and xxx.xxx with your eth1 IP address as shown in `ifconfig eth1`) this will catch all traffic between you and another IP on your ISP local segment thats NOT talking to the gateway router paste 50 lines or so of the output of this here and maybe we can figure out whats going on. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos - Instant message from any web browser! Try the new Yahoo! Canada Messenger for the Web BETA___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow
sorry. it should be 2 networks /21 4 networks /22 /22 or 16 networks /24 Thank you John R Pierce [EMAIL PROTECTED] wrote: chloe K wrote: you have the network /20 so that you got this neigbour overlfow you should subnet it no, no, NO. his eth1 connection is from his ISP. He /has/ to use the supplied netmask, he can't reconfigure their network segment. now, why is ARP table is overflowing is another issue entirely. Thomas, can you try this? Do arp -an | grep 65.188.0.1 and pick out the MAC address of your gateway router, this will look something like... ? (65.188.0.1) at 00:17:CB:4F:97:81 [ether] on eth1 So, the MAC address above is 00:17:CB:4F:97:81 ... yours definitely will be different now, # tcpdump -i eth1 -n ip host 65.188.xxx.xxx and not ether host 00:17:CB:4F:97:81 (replacing that with your gateway router's MAC address as determined from that ARP command, and xxx.xxx with your eth1 IP address as shown in `ifconfig eth1`) this will catch all traffic between you and another IP on your ISP local segment thats NOT talking to the gateway router paste 50 lines or so of the output of this here and maybe we can figure out whats going on. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos - Now with a new friend-happy design! Try the new Yahoo! Canada Messenger___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow
chloe K wrote: no. he can subnet it Typically ISP can assign /20. but client can subnet it he is on a cable modem, with a single IP on his neighborhood segment. how exactly does he subnet this? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow
On Mon, Dec 1, 2008 at 3:25 PM, chloe K [EMAIL PROTECTED] wrote: John R Pierce [EMAIL PROTECTED] wrote: chloe K wrote: you have the network /20 so that you got this neigbour overlfow you should subnet it no, no, NO. his eth1 connection is from his ISP. He /has/ to use the supplied netmask, he can't reconfigure their network segment. no. he can subnet it Typically ISP can assign /20. but client can subnet it two networks /22 /22 or 16 networks /24 No, actually he CANNOT subnet it. First the network segment wasn't assigned to him at all, he is 1 node in the ISP's network segment. Second the ISP's default gateway is 65.188.0.1 and he can get any IP in that segment, which means if he tries for force segmentation on it he will most likely end up making his default route unreachable. It is probably the result of a broadcast storm or some type of icmp flood attack on the segment. Shorten the lifetime of the ARPs in the table for that interface and/or disable ARPs on that interface and set manual ARP entries for the routers. -Ross ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow
Thomas Dukes wrote: Any ideas? How many entries do you have in the arp table? arp -a | wc -l should show you. If you really have lots of entries in there you should try to find out the reason for that. Ralph pgptXMZ7Hho95.pgp Description: PGP signature ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow
Robert Moskowitz [EMAIL PROTECTED] wrote:
Thomas Dukes wrote:
*From:* [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
*On Behalf Of *chloe K
*Sent:* Thursday, November 27, 2008 9:10 PM
*To:* CentOS mailing list
*Subject:* Re: [CentOS] Neighbour table overflow
what is your netmask?
eth0 = 255.255.240.0
Why do you have such a large subnet? There are a number of potential
performance problems with such a setup. I typically only see this in
large, bridged wireless campuses. Little justification for it in a
wired network. (I do have lots of networking experience and knowledge,
having consulted with a number of large deployments).
Even with a large subnet, you should not be arping everywhere. Either
two things are happening:
Your system is recording every ARP request it sees ('Who has IP
x.x.x.x') to avoid arping later. Bad behaviour (IMNSHO), given your
network.
Your system is ARPing for every IP address in the subnet to learn all of
its neighbors. WHy would it do that? Unless you have some snooping
software running on your system.
Hi Robert,
I did not set this value. Something did but not me.
I am on a roadrunner connection with a dynamic ip. What do you suggest I
change it to?
Thnaks!!
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Re: [CentOS] Neighbour table overflow
[EMAIL PROTECTED] wrote:
Robert Moskowitz [EMAIL PROTECTED] wrote:
Thomas Dukes wrote:
*From:* [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
*On Behalf Of *chloe K
*Sent:* Thursday, November 27, 2008 9:10 PM
*To:* CentOS mailing list
*Subject:* Re: [CentOS] Neighbour table overflow
what is your netmask?
eth0 = 255.255.240.0
Why do you have such a large subnet? There are a number of potential
performance problems with such a setup. I typically only see this in
large, bridged wireless campuses. Little justification for it in a
wired network. (I do have lots of networking experience and knowledge,
having consulted with a number of large deployments).
Even with a large subnet, you should not be arping everywhere. Either
two things are happening:
Your system is recording every ARP request it sees ('Who has IP
x.x.x.x') to avoid arping later. Bad behaviour (IMNSHO), given your
network.
Your system is ARPing for every IP address in the subnet to learn all of
its neighbors. WHy would it do that? Unless you have some snooping
software running on your system.
Hi Robert,
I did not set this value. Something did but not me.
I am on a roadrunner connection with a dynamic ip. What do you suggest I
change it to?
You might not have much control over it if you are using DHCP.
route -n
will supply you with your router address. Once you now that and your
assigned IP address (and lease) you can use ifconfig to change your
netmask so that your router and you are in the same subnet.
What is the address also of your nameserver (/etc/resolv.conf) and mail
server? If these are also within that hugh subnet, your netmask has to
keep them 'local'.
Roadrunner hmm.
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Re: [CentOS] Neighbour table overflow
[EMAIL PROTECTED] wrote:
Robert Moskowitz [EMAIL PROTECTED] wrote:
Thomas Dukes wrote:
*From:* [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
*On Behalf Of *chloe K
*Sent:* Thursday, November 27, 2008 9:10 PM
*To:* CentOS mailing list
*Subject:* Re: [CentOS] Neighbour table overflow
what is your netmask?
eth0 = 255.255.240.0
Why do you have such a large subnet? There are a number of potential
performance problems with such a setup. I typically only see this in
large, bridged wireless campuses. Little justification for it in a
wired network. (I do have lots of networking experience and knowledge,
having consulted with a number of large deployments).
Even with a large subnet, you should not be arping everywhere. Either
two things are happening:
Your system is recording every ARP request it sees ('Who has IP
x.x.x.x') to avoid arping later. Bad behaviour (IMNSHO), given your
network.
Your system is ARPing for every IP address in the subnet to learn all of
its neighbors. WHy would it do that? Unless you have some snooping
software running on your system.
Hi Robert,
I did not set this value. Something did but not me.
I am on a roadrunner connection with a dynamic ip. What do you suggest I
change it to?
If you restart your network services (Does RR use PPPoE?) you should
then have an empty ARP table.
How long does it take to overflow? Can you run TCPDUMP and see if you
are sending out the ARPs or your system is just building its table based
on heard ARP requests?
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Re: [CentOS] Neighbour table overflow
you have the network /20 so that you got this neigbour overlfow
you should subnet it
Robert Moskowitz [EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
Robert Moskowitz wrote:
Thomas Dukes wrote:
*From:* [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
*On Behalf Of *chloe K
*Sent:* Thursday, November 27, 2008 9:10 PM
*To:* CentOS mailing list
*Subject:* Re: [CentOS] Neighbour table overflow
what is your netmask?
eth0 = 255.255.240.0
Why do you have such a large subnet? There are a number of potential
performance problems with such a setup. I typically only see this in
large, bridged wireless campuses. Little justification for it in a
wired network. (I do have lots of networking experience and knowledge,
having consulted with a number of large deployments).
Even with a large subnet, you should not be arping everywhere. Either
two things are happening:
Your system is recording every ARP request it sees ('Who has IP
x.x.x.x') to avoid arping later. Bad behaviour (IMNSHO), given your
network.
Your system is ARPing for every IP address in the subnet to learn all of
its neighbors. WHy would it do that? Unless you have some snooping
software running on your system.
Hi Robert,
I did not set this value. Something did but not me.
I am on a roadrunner connection with a dynamic ip. What do you suggest I
change it to?
You might not have much control over it if you are using DHCP.
route -n
will supply you with your router address. Once you now that and your
assigned IP address (and lease) you can use ifconfig to change your
netmask so that your router and you are in the same subnet.
What is the address also of your nameserver (/etc/resolv.conf) and mail
server? If these are also within that hugh subnet, your netmask has to
keep them 'local'.
Roadrunner hmm.
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Re: [CentOS] Neighbour table overflow
Hi, On Fri, Nov 28, 2008 at 07:20, Thomas Dukes [EMAIL PROTECTED] wrote: When I ran the above, I'm not sure I'm getting a correct response. It takes serval miuntes then returns: Printk: 100 messages suppressed Neighbour table overflow Printk: 15 messages suppressed 3 It looks like you have only 3 lines in your arp table, so it's really hard to understand how it would overflow from that. What does the output of arp -a look like? You can also look at: cat /proc/net/arp Please post the output of: sysctl -a | grep neigh Do you have IPv6 enabled? Filipe ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow
On Fri, Nov 28, 2008 at 9:35 AM, chloe K [EMAIL PROTECTED] wrote: you have the network /20 so that you got this neigbour overlfow you should subnet it Robert Moskowitz [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: : To EVERYONE who is top-posting on this list: Stop it. Thank you. mhr ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
RE: [CentOS] Neighbour table overflow
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
Of Robert Moskowitz
Sent: Friday, November 28, 2008 12:20 PM
To: CentOS mailing list
Subject: Re: [CentOS] Neighbour table overflow
[EMAIL PROTECTED] wrote:
Robert Moskowitz [EMAIL PROTECTED] wrote:
Thomas Dukes wrote:
*From:* [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
*On Behalf Of *chloe K
*Sent:* Thursday, November 27, 2008 9:10 PM
*To:* CentOS mailing list
*Subject:* Re: [CentOS] Neighbour table overflow
what is your netmask?
eth0 = 255.255.240.0
Why do you have such a large subnet? There are a number of potential
performance problems with such a setup. I typically only see this in
large, bridged wireless campuses. Little justification for it in a
wired network. (I do have lots of networking experience and
knowledge, having consulted with a number of large deployments).
Even with a large subnet, you should not be arping everywhere.
Either two things are happening:
Your system is recording every ARP request it sees ('Who has IP
x.x.x.x') to avoid arping later. Bad behaviour (IMNSHO), given your
network.
Your system is ARPing for every IP address in the subnet to learn all
of its neighbors. WHy would it do that? Unless you have some
snooping software running on your system.
Hi Robert,
I did not set this value. Something did but not me.
I am on a roadrunner connection with a dynamic ip. What do you suggest I
change it to?
You might not have much control over it if you are using DHCP.
route -n
Here's the output from route -n:
Kernel IP routing table
Destination Gateway Genmask Flags Metric RefUse
Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 00 eth1
65.188.0.0 0.0.0.0 255.255.240.0 U 0 00 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 00 eth1
0.0.0.0 65.188.0.1 0.0.0.0 UG0 00 eth0
will supply you with your router address. Once you now that and your
assigned IP address (and lease) you can use ifconfig to change your netmask
so that your router and you are in the same subnet.
What is the address also of your nameserver (/etc/resolv.conf) and mail
server? If these are also within that hugh subnet, your netmask has to keep
them 'local'.
My nameservers are: 24.25.5.149 and 24.25.5.150
Mailservers: 75.180.132.77 and 75.180.132.33
Roadrunner hmm.
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RE: [CentOS] Neighbour table overflow
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
Of Robert Moskowitz
Sent: Friday, November 28, 2008 12:28 PM
To: CentOS mailing list
Subject: Re: [CentOS] Neighbour table overflow
[EMAIL PROTECTED] wrote:
Robert Moskowitz [EMAIL PROTECTED] wrote:
Thomas Dukes wrote:
*From:* [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
*On Behalf Of *chloe K
*Sent:* Thursday, November 27, 2008 9:10 PM
*To:* CentOS mailing list
*Subject:* Re: [CentOS] Neighbour table overflow
what is your netmask?
eth0 = 255.255.240.0
Why do you have such a large subnet? There are a number of potential
performance problems with such a setup. I typically only see this in
large, bridged wireless campuses. Little justification for it in a
wired network. (I do have lots of networking experience and
knowledge, having consulted with a number of large deployments).
Even with a large subnet, you should not be arping everywhere.
Either two things are happening:
Your system is recording every ARP request it sees ('Who has IP
x.x.x.x') to avoid arping later. Bad behaviour (IMNSHO), given your
network.
Your system is ARPing for every IP address in the subnet to learn all
of its neighbors. WHy would it do that? Unless you have some
snooping software running on your system.
Hi Robert,
I did not set this value. Something did but not me.
I am on a roadrunner connection with a dynamic ip. What do you suggest I
change it to?
If you restart your network services (Does RR use PPPoE?) you should then
have an empty ARP table.
How long does it take to overflow? Can you run TCPDUMP and see if you are
sending out the ARPs or your system is just building its table based on
heard ARP requests?
It takes aout 5 -10 minutes before I see the messages. I don't know you
meant by the last question. I ran TCPDUMP and page after page after page of
stuff is scrolling.
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Re: [CentOS] Neighbour table overflow
chloe K wrote: you have the network /20 so that you got this neigbour overlfow you should subnet it no, no, NO. his eth1 connection is from his ISP. He /has/ to use the supplied netmask, he can't reconfigure their network segment. now, why is ARP table is overflowing is another issue entirely. Thomas, can you try this? Do arp -an | grep 65.188.0.1 and pick out the MAC address of your gateway router, this will look something like... ? (65.188.0.1) at 00:17:CB:4F:97:81 [ether] on eth1 So, the MAC address above is 00:17:CB:4F:97:81 ... yours definitely will be different now, # tcpdump -i eth1 -n ip host 65.188.xxx.xxx and not ether host 00:17:CB:4F:97:81 (replacing that with your gateway router's MAC address as determined from that ARP command, and xxx.xxx with your eth1 IP address as shown in `ifconfig eth1`) this will catch all traffic between you and another IP on your ISP local segment thats NOT talking to the gateway router paste 50 lines or so of the output of this here and maybe we can figure out whats going on. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
RE: [CentOS] Neighbour table overflow
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John R Pierce Sent: Friday, November 28, 2008 5:14 PM To: CentOS mailing list Subject: Re: [CentOS] Neighbour table overflow chloe K wrote: you have the network /20 so that you got this neigbour overlfow you should subnet it no, no, NO. his eth1 connection is from his ISP. He /has/ to use the supplied netmask, he can't reconfigure their network segment. now, why is ARP table is overflowing is another issue entirely. Thomas, can you try this? Do arp -an | grep 65.188.0.1 Hi John, The output from arp -an | grep 65.188.0.1 is: ? (65.188.0.1) at 00:1B:54:CB:7A::05 and pick out the MAC address of your gateway router, this will look something like... ? (65.188.0.1) at 00:17:CB:4F:97:81 [ether] on eth1 So, the MAC address above is 00:17:CB:4F:97:81 ... yours definitely will be different now, # tcpdump -i eth1 -n ip host 65.188.xxx.xxx and not ether host 00:17:CB:4F:97:81 (replacing that with your gateway router's MAC address as determined from that ARP command, and xxx.xxx with your eth1 IP address as shown in `ifconfig eth1`) this will catch all traffic between you and another IP on your ISP local segment thats NOT talking to the gateway router paste 50 lines or so of the output of this here and maybe we can figure out whats going on. OK, I think you lost me on that last part. I ran tcpdump -i eth1 -n ip host 65.188.0.1 and got: Tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth1, link-type EN10MB (Ethernet), capture size 96 bytes 0 packets captred 0 packets received by filter 0 packets dropped by kernel Thanks!! ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow
Thomas Dukes wrote: # tcpdump -i eth1 -n ip host 65.188.xxx.xxx and not ether host 00:17:CB:4F:97:81 ... OK, I think you lost me on that last part. I ran tcpdump -i eth1 -n ip host 65.188.0.1 and got: no, no. I said... # tcpdump -i eth0 -n ip host 65.188.xxx.xxx and not ether host xx:xx:xx:xx:xx:xx thats all one line. the first xxx.xxx would be replaced with those fields from your IP address not the gateway, and the latter xx:xx:xx:xx:xx:xx would be replaced with the MAC address of your ISP's default router, as discovered via the other command I listed. I guess this is just too complicated to do over email... I recommend you find someone local to you who is versed in network troubleshooting. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] Neighbour table overflow
Just started getting this. I tried the following by adding it to my etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 4096 net.ipv4.neigh.default.gc_thresh2 = 8192 net.ipv4.neigh.default.gc_thresh3 = 8192 net.ipv4.neigh.default.base_reachable_time = 86400 net.ipv4.neigh.default.gc_stale_time = 86400 That pretty much locked things up. Then I tried another googled solution: echo 256 /proc/sys/net/ipv4/neigh/default/gc_thresh1 echo 512 /proc/sys/net/ipv4/neigh/default/gc_thresh2 echo 1024 /proc/sys/net/ipv4/neigh/default/gc_thresh3 And adding it also to etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 256 net.ipv4.neigh.default.gc_thresh2 = 512 net.ipv4.neigh.default.gc_thresh3 = 1024 Still not working. Any ideas? TIA ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow
what is your netmask? Thomas Dukes [EMAIL PROTECTED] wrote: Just started getting this. I tried the following by adding it to my etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 4096 net.ipv4.neigh.default.gc_thresh2 = 8192 net.ipv4.neigh.default.gc_thresh3 = 8192 net.ipv4.neigh.default.base_reachable_time = 86400 net.ipv4.neigh.default.gc_stale_time = 86400 That pretty much locked things up. Then I tried another googled solution: echo 256 /proc/sys/net/ipv4/neigh/default/gc_thresh1 echo 512 /proc/sys/net/ipv4/neigh/default/gc_thresh2 echo 1024 /proc/sys/net/ipv4/neigh/default/gc_thresh3 And adding it also to etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 256 net.ipv4.neigh.default.gc_thresh2 = 512 net.ipv4.neigh.default.gc_thresh3 = 1024 Still not working. Any ideas? TIA ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos - Yahoo! Canada Toolbar : Search from anywhere on the web and bookmark your favourite sites. Download it now! ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
RE: [CentOS] Neighbour table overflow
_ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of chloe K Sent: Thursday, November 27, 2008 9:10 PM To: CentOS mailing list Subject: Re: [CentOS] Neighbour table overflow what is your netmask? eth0 = 255.255.240.0 eth1 = 255.255.255.0 lo = 255.0.0.0 These don't look right except for eth1. I have made no changes to these in about 4 years. Thanks Thomas Dukes [EMAIL PROTECTED] wrote: Just started getting this. I tried the following by adding it to my etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 4096 net.ipv4.neigh.default.gc_thresh2 = 8192 net.ipv4.neigh.default.gc_thresh3 = 8192 net.ipv4.neigh.default.base_reachable_time = 86400 net.ipv4.neigh.default.gc_stale_time = 86400 That pretty much locked things up. Then I tried another googled solution: echo 256 /proc/sys/net/ipv4/neigh/default/gc_thresh1 echo 512 /proc/sys/net/ipv4/neigh/default/gc_thresh2 echo 1024 /proc/sys/net/ipv4/neigh/default/gc_thresh3 And adding it also to etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 256 net.ipv4.neigh.default.gc_thresh2 = 512 net.ipv4.neigh.default.gc_thresh3 = 1024 Still not working. Any ideas? TIA ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos _ http://us.i1.yimg.com/us.yimg.com/i/ca/iotg_search.jpg http://ca.toolbar.yahoo.com/ Yahoo! Canada Toolbar : Search from anywhere on the web and bookmark your favourite sites. Download it now! ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow
Thomas Dukes wrote: *From:* [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] *On Behalf Of *chloe K *Sent:* Thursday, November 27, 2008 9:10 PM *To:* CentOS mailing list *Subject:* Re: [CentOS] Neighbour table overflow what is your netmask? eth0 = 255.255.240.0 That is 4096 addresses (256*16). eth1 = 255.255.255.0 lo = 255.0.0.0 lo is correct. The 'whole' net127. Of which 4 addresses have ever been used (that I have encountered) These don't look right except for eth1. I have made no changes to these in about 4 years. Thanks */Thomas Dukes [EMAIL PROTECTED]/* wrote: Just started getting this. I tried the following by adding it to my etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 4096 net.ipv4.neigh.default.gc_thresh2 = 8192 net.ipv4.neigh.default.gc_thresh3 = 8192 net.ipv4.neigh.default.base_reachable_time = 86400 net.ipv4.neigh.default.gc_stale_time = 86400 That pretty much locked things up. Then I tried another googled solution: echo 256 /proc/sys/net/ipv4/neigh/default/gc_thresh1 echo 512 /proc/sys/net/ipv4/neigh/default/gc_thresh2 echo 1024 /proc/sys/net/ipv4/neigh/default/gc_thresh3 And adding it also to etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 256 net.ipv4.neigh.default.gc_thresh2 = 512 net.ipv4.neigh.default.gc_thresh3 = 1024 Still not working. Any ideas? TIA ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos *Yahoo! Canada Toolbar :* Search from anywhere on the web and bookmark your favourite sites. Download it now! http://ca.toolbar.yahoo.com/ ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] Neighbour table overflow.
Hi, I am getting below error on mailgw. it has 2 ethernets. eth0 is connected to internet, while eth1 is connected to LAN where there are about 300 PCs. Mar 12 09:14:00 gateway kernel: NET: 697 messages suppressed. Mar 12 09:14:00 gateway kernel: Neighbour table overflow. Mar 12 09:14:05 gateway kernel: NET: 660 messages suppressed. Mar 12 09:14:05 gateway kernel: Neighbour table overflow. Mar 12 09:14:10 gateway kernel: NET: 682 messages suppressed. Mar 12 09:14:10 gateway kernel: Neighbour table overflow. Mar 12 09:14:15 gateway kernel: NET: 700 messages suppressed. Mar 12 09:14:15 gateway kernel: Neighbour table overflow. Mar 12 09:14:20 gateway kernel: NET: 633 messages suppressed. Mar 12 09:14:20 gateway kernel: Neighbour table overflow. it happens very often. I goolgled and found some info. many talk about below file /proc/sys/net/ipv4/neigh/default/gc_thresh1 I increased its value to 300 But, i still get the same error. any help ? -- Thank you Indunil Jayasooriya ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Neighbour table overflow.
On Wed, Mar 12, 2008 at 10:12:19AM +0530, Indunil Jayasooriya alleged: Hi, I am getting below error on mailgw. it has 2 ethernets. eth0 is connected to internet, while eth1 is connected to LAN where there are about 300 PCs. Mar 12 09:14:00 gateway kernel: NET: 697 messages suppressed. Mar 12 09:14:00 gateway kernel: Neighbour table overflow. Mar 12 09:14:05 gateway kernel: NET: 660 messages suppressed. Mar 12 09:14:05 gateway kernel: Neighbour table overflow. Mar 12 09:14:10 gateway kernel: NET: 682 messages suppressed. Mar 12 09:14:10 gateway kernel: Neighbour table overflow. Mar 12 09:14:15 gateway kernel: NET: 700 messages suppressed. Mar 12 09:14:15 gateway kernel: Neighbour table overflow. Mar 12 09:14:20 gateway kernel: NET: 633 messages suppressed. Mar 12 09:14:20 gateway kernel: Neighbour table overflow. it happens very often. I goolgled and found some info. many talk about below file /proc/sys/net/ipv4/neigh/default/gc_thresh1 I increased its value to 300 But, i still get the same error. The default is only applied to devices as they come up. You'll need to also increase the values in the interface-specific directories. Be sure to also adjust your /etc/sysctl.conf because manually playing in /proc won't survive a reboot. In my very large flat network, I have the following in /etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 4096 net.ipv4.neigh.default.gc_thresh2 = 8192 net.ipv4.neigh.default.gc_thresh3 = 8192 net.ipv4.neigh.default.base_reachable_time = 86400 net.ipv4.neigh.default.gc_stale_time = 86400 These are documented in arp(7). -- Garrick Staples, GNU/Linux HPCC SysAdmin University of Southern California Please avoid sending me Word or PowerPoint attachments. See http://www.gnu.org/philosophy/no-word-attachments.html pgpMUpYJSK2Ik.pgp Description: PGP signature ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
