arpd not working in 2.4.17 or 2.5.1
Hi All,
I am running 2.5.1 kernel on a 2 AMD processor system and have enable routing messages, netlink and arpd support inside kernel as described in arpd docs.
Then after making 36 character devices, when I run arpd, it's starts up but always keeps silent (strace) and the kernel also does not keep it's 256 arp address limit.
Pls help fix it, I need linux to be able to talk to more than 1024 clients.
Thanks in Advance.
Latest kernel I saw working with arpd (user space daemon) I am manteining is 2.2.16, then from 2.4.4 (for 2.4 series), some changes were done to kernel so that the kernel does not talk correctly with the device /dev/arpd anymore.
It is not the first time I write about this on lkml, but it seems none is interested in manteining the kernel space component for arpd support. I did some investigation, but the code for arpd support itself inside of the kernel seems to be ok, something else is wrong with neighour.c.
So at less I can say the user space daemon works well on 2.2.16 I have around ;).
Luigi
Quoted 27 lines · Amit Gupta
Hi All,
I am running 2.5.1 kernel on a 2 AMD processor system and have enable routing messages, netlink and arpd support inside kernel as described in arpd docs.
Then after making 36 character devices, when I run arpd, it's starts up but always keeps silent (strace) and the kernel also does not keep it's 256 arp address limit.
Pls help fix it, I need linux to be able to talk to more than 1024 clients.
Thanks in Advance.
-
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But arp>1024 is Very Important, else linux will never be able to talk to more than 1024 clients !
Linux is my favourite and I wonder if this limit will kill linux for the race with Solaris/M$ server market. So pls save me :) and help neighour.c/network layer in new kernel.
Thanks in Advance.
Quoted 43 lines · Luigi Genoni
Latest kernel I saw working with arpd (user space daemon) I am manteining is 2.2.16, then from 2.4.4 (for 2.4 series), some changes were done to kernel so that the kernel does not talk correctly with the device
/dev/arpdanymore.
It is not the first time I write about this on lkml, but it seems none is interested in manteining the kernel space component for arpd support. I did some investigation, but the code for arpd support itself inside of the kernel seems to be ok, something else is wrong withneighour.c.So at less I can say the user space daemon works well on 2.2.16 I have around ;).
Luigi
Quoted 27 lines · Amit Gupta
Hi All,
I am running 2.5.1 kernel on a 2 AMD processor system and have enable routing messages, netlink and arpd support inside kernel as described in arpd docs.
Then after making 36 character devices, when I run arpd, it's starts up but always keeps silent (strace) and the kernel also does not keep it's 256 arp address limit.
Pls help fix it, I need linux to be able to talk to more than 1024 clients.
Thanks in Advance.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Quoted 6 lines
But arp>1024 is Very Important, else linux will never be able to talk to more than 1024 clients !
Linux is my favourite and I wonder if this limit will kill linux for the race with Solaris/M$ server market. So pls save me :) and help neighour.c/network layer in new kernel.
ARP applies for local links only. So you need a network you are actively talking to 1024 different hosts directly on. Furthermore all the config items should now be soft anyway. Want more, enable more.
Quoted 10 lines · Alan Cox
Quoted 6 lines
But arp>1024 is Very Important, else linux will never be able to talk to more than 1024 clients !
Linux is my favourite and I wonder if this limit will kill linux for the race with Solaris/M$ server market. So pls save me :) and help neighour.c/network layer in new kernel.
ARP applies for local links only. So you need a network you are actively talking to 1024 different hosts directly on. Furthermore all the config items should now be soft anyway. Want more, enable more.
To have this kind of network is not impossible at all, I received mail from people at intel who are dealing with around 5000 arp (they say). In this situation with arpd there was no sensible performance loss, right now there is a big slowdown.
We do have more than 1024 systems dircetly connected using switches.. and I am working on getting a "lsf linux server master", which requires to open connections all the machines in almost every second or so. Everthing works fine but as soon as the master daemon tries to connect to systems >1024.. arp kills it with
Jan 15 08:54:08 lx-master kernel: NET: 464 messages suppressed. Jan 15 08:54:08 lx-master kernel: Neighbour table overflow. Jan 15 08:54:08 lx-master last message repeated 9 times Jan 15 08:54:54 lx-master kernel: NET: 442 messages suppressed. Jan 15 08:54:54 lx-master kernel: Neighbour table overflow. Jan 15 08:54:54 lx-master last message repeated 8 times Jan 15 08:56:24 lx-master kernel: NET: 443 messages suppressed. Jan 15 08:56:24 lx-master kernel: Neighbour table overflow.
-Amit
Quoted 17 lines · Luigi Genoni
Quoted 10 lines · Alan Cox
Quoted 6 lines
But arp>1024 is Very Important, else linux will never be able to talk to more than 1024 clients !
Linux is my favourite and I wonder if this limit will kill linux for the race with Solaris/M$ server market. So pls save me :) and help neighour.c/network layer in new kernel.
ARP applies for local links only. So you need a network you are actively talking to 1024 different hosts directly on. Furthermore all the config items should now be soft anyway. Want more, enable more.
To have this kind of network is not impossible at all, I received mail from people at intel who are dealing with around 5000 arp (they say). In this situation with arpd there was no sensible performance loss, right now there is a big slowdown.
Hello!
Quoted 1 line
the master daemon tries to connect to systems >1024.. arp kills it with
Make echo 2048 > /proc/sys/net/ipv4/neigh/default/gc_thresh3 and live in peace.
arpd will _not_ help you at all. Without tuning above you are lost in any case, with this tuning arpd is useless.
Not quite useless though, but its task has nothing to do with size of table. Its task is reducing broadcasting on LAN, which is importnat but a second order effect yet. Well, you can use arpd from iproute2.
Alexey