Duplicate IP and MAC address ARP issue
Subsystems (2)
Dear guys,
I am building a linux box base on linux kernel 2.4.31 and I can modify the source code but can not change to other version. eveything is ok until I connect my box to Netgear POE switch, this switch will send ARP request packet back to box, then box's network will "down", and can not send out any IP packet except ARP.
test environment:
----------------------------------------------
| 10Mbps HUB |
| |
----------------------------------------------
| | |
| | |
--------------------- | ----------------------
| Linux 2.4.31 | | | Netgear POE switch |
| 192.168.0.155 | | | FS108P |
| 00:0e:e9:80:22:60 | | | |
--------------------- | ----------------------
|
--------------------- |
| my laptop | |
| 192.168.0.8 |--|
| 00:15:58:7c:b9:1d |
--------------------- I found that linux box works fine before I connect netgear POE switch to the same HUB.
I discovered netgear switch will forward ARP request which receive from HUB back to HUB, linux box will be sick after he receive this same package.
What I have tried: (arp.c, route.c, ip_input.c locate in \linux-2.4.31\net\ipv4\)
1. add some code in front of arp_rcv()/arp.c to detect/drop the ARP request packet which send back by switch, but not work.
since arp_rcv() is called by device layer and it will drop the wrong ARP packet, I thought this packet should not affect the box, but the fact is there.
2. discovered skb->dst will be NULL in ip_rcv_finish()/ip_input.c when box didn't receive wrong packet, but after box receive wrong packet, skb->dst will hold something, so ip_rcv_finish() will not call ip_route_input(), even I get rid of the judgement of "if (skb->dst == NULL)", ip_route_input() will return failed.
static inline int ip_rcv_finish(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
struct iphdr *iph = skb->nh.iph;
/*
* Initialise the virtual path cache for the packet. It describes
* how the packet travels inside Linux networking.
*/
if (skb->dst == NULL) {
if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev)) goto drop;
}
...
some other informaion:
# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0E:E9:80:22:60
inet addr:192.168.0.155 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:7 errors:0 dropped:0 overruns:0 frame:0
TX packets:216 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:676 (676.0 B) TX bytes:9072 (8.8 KiB)
Interrupt:39
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:78 errors:0 dropped:0 overruns:0 frame:0
TX packets:78 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:6708 (6.5 KiB) TX bytes:6708 (6.5 KiB)
# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth0
0.0.0.0 192.168.0.2 0.0.0.0 UG 0 0 0 eth0
(note: when I connect switch to HUB, route -n will output the same message)Another clue which I found is when box occur this problem, several "ifconfig eth0 up" can make the network of box work again, but it will still fail after receive wrong ARP packet.
I have no idea how to fix this problem, it has spent me more than two weeks and beyond my ability, so it is very appreciated if anyone can help me, thank you!
Best regards,
Watson
2008-12-15
---------------------------------
Email: [email protected]
A message that is not in the archive (sent off-list or not yet received): 013801c95e90$5fe737e0$4491a8c0@xiwang
Dear xiwang,
I know that this problem is cause by switch, but what I cann do is to let linux box accommodate this situation.
I have captured the packets, it shows that netgear switch just forward the same arp request without modifying anything, so the packet is totally the SAME.
Best regards,
Watson
2008-12-15
---------------------------------
Email: [email protected]
======= 2008-12-15 16:35:18 You wrote：=======
Quoted 127 lines
why the packet return from switch? usually, the switch don't return back the orig-packet.
refering to your description, i think the packet return back to linux box, the packet already changed. so you can sniffer the packet from switch and from linux box, compare the packet, if is there a different on SMAC field.
-----邮件原件-----
发件人: [email protected] [mailto:[email protected]. org] 代表 watson
发送时间: 2008年12月15日 16:06
收件人: [email protected]; [email protected]
主题: [problem] Duplicate IP and MAC address ARP issueDear guys,
I am building a linux box base on linux kernel 2.4.31 and I can modify the source code but can not change to other version.
eveything is ok until I connect my box to Netgear POE switch, this switch will send ARP request packet back to box,
then box's network will "down", and can not send out any IP packet except ARP.test environment:
----------------------------------------------| 10Mbps HUB | | | ---------------------------------------------- | | | | | | --------------------- | ---------------------- | Linux 2.4.31 | | | Netgear POE switch | | 192.168.0.155 | | | FS108P | | 00:0e:e9:80:22:60 | | | | --------------------- | ---------------------- | --------------------- | | my laptop | | | 192.168.0.8 |--| | 00:15:58:7c:b9:1d | ---------------------I found that linux box works fine before I connect netgear POE switch to the same HUB.
I discovered netgear switch will forward ARP request which receive from HUB back to HUB, linux box will be sick after he receive this same package.What I have tried: (
arp.c,route.c,ip_input.clocate in \linux-2.4.31\net\ipv4\)
1. add some code in front of arp_rcv()/arp.c to detect/drop the ARP request packet which send back by switch, but not work.
sincearp_rcv()is called by device layer and it will drop the wrong ARP packet, I thought this packet should not affect the box, but the fact is there.
2. discoveredskb->dstwill be NULL in ip_rcv_finish()/ip_input.c when box didn't receive wrong packet, but after box receive wrong packet,skb->dstwill hold something,
soip_rcv_finish()will not callip_route_input(), even I get rid of the judgement of "if (skb->dst== NULL)",ip_route_input()will return failed.static inline int
ip_rcv_finish(struct sk_buff *skb)
{
structnet_device*dev =skb->dev;
struct iphdr *iph =skb->nh.iph;
/*
* Initialise the virtual path cache for the packet. It describes
* how the packet travels inside Linux networking.
*/
if (skb->dst== NULL) {
if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev)) goto drop;
}
...some other informaion:
# ifconfig eth0 Link encap:Ethernet HWaddr 00:0E:E9:80:22:60 inet addr:192.168.0.155 Bcast:192.168.0.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7 errors:0 dropped:0 overruns:0 frame:0 TX packets:216 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:676 (676.0 B) TX bytes:9072 (8.8 KiB) Interrupt:39 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:78 errors:0 dropped:0 overruns:0 frame:0 TX packets:78 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:6708 (6.5 KiB) TX bytes:6708 (6.5 KiB) # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth0 0.0.0.0 192.168.0.2 0.0.0.0 UG 0 0 0 eth0 (note: when I connect switch to HUB, route -n will output the same message)Another clue which I found is when box occur this problem, several "ifconfig eth0 up" can make the network of box work again, but it will still fail after receive wrong ARP packet.
I have no idea how to fix this problem, it has spent me more than two weeks and beyond my ability, so it is very appreciated if anyone can help me, thank you!
Best regards,
Watson2008-12-15
---------------------------------
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guys,
I believe there are some code in linux kernel which lead to this issue, but can not find it out.
Is there anybody who familiar with kernel-net code, please help to take a look at this problem and give me some advice, thank you!
Best regards,
Watson
2008-12-15
---------------------------------
Email: [email protected]
----------------Original Message----------------
From: watson [mailto：[email protected]]
Quoted 75 lines
Dear guys,
I am building a linux box base on linux kernel 2.4.31 and I can modify the source code but can not change to other version. eveything is ok until I connect my box to Netgear POE switch, this switch will send ARP request packet back to box, then box's network will "down", and can not send out any IP packet except ARP.
test environment:
----------------------------------------------| 10Mbps HUB | | | ---------------------------------------------- | | | | | | --------------------- | ---------------------- | Linux 2.4.31 | | | Netgear POE switch | | 192.168.0.155 | | | FS108P | | 00:0e:e9:80:22:60 | | | | --------------------- | ---------------------- | --------------------- | | my laptop | | | 192.168.0.8 |--| | 00:15:58:7c:b9:1d | ---------------------I found that linux box works fine before I connect netgear POE switch to the same HUB.
I discovered netgear switch will forward ARP request which receive from HUB back to HUB, linux box will be sick after he receive this same package.What I have tried: (
arp.c,route.c,ip_input.clocate in \linux-2.4.31\net\ipv4\)
1. add some code in front of arp_rcv()/arp.c to detect/drop the ARP request packet which send back by switch, but not work.
sincearp_rcv()is called by device layer and it will drop the wrong ARP packet, I thought this packet should not affect the box, but the fact is there.
2. discoveredskb->dstwill be NULL in ip_rcv_finish()/ip_input.c when box didn't receive wrong packet, but after box receive wrong packet,skb->dstwill hold something, soip_rcv_finish()will not callip_route_input(), even I get rid of the judgement of "if (skb->dst== NULL)",ip_route_input()will return failed.static inline int
ip_rcv_finish(struct sk_buff *skb)
{
structnet_device*dev =skb->dev;
struct iphdr *iph =skb->nh.iph;
/*
* Initialise the virtual path cache for the packet. It describes
* how the packet travels inside Linux networking.
*/
if (skb->dst== NULL) {
if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev)) goto drop;
}
...some other informaion:
# ifconfig eth0 Link encap:Ethernet HWaddr 00:0E:E9:80:22:60 inet addr:192.168.0.155 Bcast:192.168.0.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7 errors:0 dropped:0 overruns:0 frame:0 TX packets:216 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:676 (676.0 B) TX bytes:9072 (8.8 KiB) Interrupt:39 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:78 errors:0 dropped:0 overruns:0 frame:0 TX packets:78 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:6708 (6.5 KiB) TX bytes:6708 (6.5 KiB) # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eth0 0.0.0.0 192.168.0.2 0.0.0.0 UG 0 0 0 eth0 (note: when I connect switch to HUB, route -n will output the same message)Another clue which I found is when box occur this problem, several "ifconfig eth0 up" can make the network of box work again, but it will still fail after receive wrong ARP packet.
Quoted 10 lines
I have no idea how to fix this problem, it has spent me more than two weeks and beyond my ability, so it is very appreciated if anyone can help me, thank you!
Best regards,
Watson2008-12-15
---------------------------------
Email: [email protected]
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