1，正常时候的mac地址信息
[root@tonykorn97 ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:1D:09:08:A9:8D
inet addr:172.23.4.250 Bcast:172.23.4.255 Mask:255.255.255.0
inet6 addr: fe80::21d:9ff:fe08:a98d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:90056 errors:0 dropped:0 overruns:0 frame:0
TX packets:84881 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8917134 (8.5 MiB) TX bytes:19043014 (18.1 MiB)
Interrupt:169 Memory:f4000000-f4011100

2，网络不通的时候从路由器上得到的mac地址信息。
tonykorn97#show arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 172.23.4.254 - 000b.4615.4706 ARPA FastEthernet0/0
Internet 172.23.4.250 0 001d.0908.a98f ARPA FastEthernet0/0

3，其他操作
tonykorn97#ping 172.23.4.250

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.23.4.250, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 37/39/40 ms
tonykorn97#

tonykorn97#show arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 172.23.4.254 - 000b.4615.4706 ARPA FastEthernet0/0
Internet 172.23.4.250 0 001d.0908.a98d ARPA FastEthernet0/0

4，察看dmesg信息：
bnx2: eth0 NIC Link is Down
bnx2: eth0 NIC Link is Up, 1000 Mbps full duplex, receive & transmit flow control ON
bnx2: eth0 NIC Link is Down
bnx2: eth0 NIC Link is Up, 1000 Mbps full duplex, receive & transmit flow control ON

5，把另外一个ip地址启动起来后，察看ip地址信息：
eth0 Link encap:Ethernet HWaddr 00:1D:09:08:A9:8D
inet addr:172.23.4.250 Bcast:172.23.4.255 Mask:255.255.255.0
inet6 addr: fe80::21d:9ff:fe08:a98d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:180588 errors:0 dropped:0 overruns:0 frame:0
TX packets:183393 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:36726016 (35.0 MiB) TX bytes:81334474 (77.5 MiB)
Interrupt:169 Memory:f4000000-f4011100

eth1 Link encap:Ethernet HWaddr 00:1D:09:08:A9:8B
inet addr:172.23.4.252 Bcast:172.23.4.255 Mask:255.255.255.0
inet6 addr: fe80::21d:9ff:fe08:a98b/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:404 (404.0 b)
Interrupt:169 Memory:f8000000-f8011100

6，然后看到mac地址其中一个会变

tonykorn97#show arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 172.23.4.254 - 000b.4615.4706 ARPA FastEthernet0/0
Internet 172.23.4.252 4 001d.0908.a98b ARPA FastEthernet0/0
Internet 172.23.4.250 1 001d.0908.a98f ARPA FastEthernet0/0

7，把eth0从172.23.4.250变为172.23.4.251 并且停止
把eth1从252改为250

[root@tonykorn97 ~]# ifconfig
eth1 Link encap:Ethernet HWaddr 00:1D:09:08:A9:8B
inet addr:172.23.4.250 Bcast:172.23.4.255 Mask:255.255.255.0
inet6 addr: fe80::21d:9ff:fe08:a98b/64 Scope:Link

后续继续观察

观察一天，mac地址没有变

[root@tonykorn97 ~]# ifconfig
eth1 Link encap:Ethernet HWaddr 00:1D:09:08:A9:8B
inet addr:172.23.4.250 Bcast:172.23.4.255 Mask:255.255.255.0

接着发现mac地址有变为：
tonykorn97#show arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 172.23.4.254 - 000b.4615.4706 ARPA FastEthernet0/0
Internet 172.23.4.250 5 001d.0908.a98f ARPA FastEthernet0/0

mac地址：
[root@tonykorn97 ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:1D:09:08:A9:8D
inet addr:172.23.4.252 Bcast:172.23.4.255 Mask:255.255.255.0

eth1 Link encap:Ethernet HWaddr 00:1D:09:08:A9:8B
inet addr:172.23.4.250 Bcast:172.23.4.255 Mask:255.255.255.0

8，重新安装驱动

[root@tonykorn97 ~]# rpm -ivh bnx2-1.5.10c-1.src.rpm
1:bnx2 ########################################### [100%]

[root@tonykorn97 ~]# cd /usr/src/redhat/
BUILD/ RPMS/ SOURCES/ SPECS/ SRPMS/

[root@tonykorn97 redhat]# rpmbuild -bb SPECS/bnx2.spec

+ rm -rf /var/tmp/bnx2-buildroot /usr/src/redhat/BUILD/file.list.bnx2
+ exit 0
[root@tonykorn97 redhat]# ls
BUILD RPMS SOURCES SPECS SRPMS
[root@tonykorn97 redhat]# cd RPMS/
[root@tonykorn97 RPMS]# cd x86_64/
[root@tonykorn97 x86_64]# rpm -ivh bnx2-1.5.10c-1.x86_64.rpm
Preparing... ########################################### [100%]
1:bnx2 ########################################### [100%]
[root@tonykorn97 x86_64]#

[root@tonykorn97 net]# modprobe bnx2

/etc/init.d/network restart 重启network

9，发现ttl值有变化：
64 bytes from 172.23.4.250: icmp_seq=17050 ttl=125 time=44.2 ms
64 bytes from 172.23.4.250: icmp_seq=17051 ttl=125 time=44.1 ms
64 bytes from 172.23.4.250: icmp_seq=17052 ttl=125 time=45.3 ms
64 bytes from 172.23.4.250: icmp_seq=17053 ttl=61 time=10.2 ms
64 bytes from 172.23.4.250: icmp_seq=17054 ttl=61 time=10.2 ms
64 bytes from 172.23.4.250: icmp_seq=17055 ttl=61 time=10.3 ms

此时估计就是有机器中病毒了.

关闭一些服务，重启。情况还是一样.

只剩一台路由器,一台主交换机,和一个服务器.然后一直ping。看还有没有ttl值变化的。

在晚上11点到12点的时候出现问题
64 bytes from 172.23.4.250: icmp_seq=15596 ttl=61 time=10.1 ms
64 bytes from 172.23.4.250: icmp_seq=15597 ttl=61 time=10.2 ms
64 bytes from 172.23.4.250: icmp_seq=15598 ttl=125 time=64.3 ms
64 bytes from 172.23.4.250: icmp_seq=15599 ttl=125 time=44.2 ms

10，发现dmesg信息：
MSI INIT SUCCESS
bnx2: eth1: using MSI
bnx2: eth1 NIC Copper Link is Up, 1000 Mbps full duplex
lp: driver loaded but no devices found
NET: Registered protocol family 10
Disabled Privacy Extensions on device ffffffff80405540(lo)
IPv6 over IPv4 tunneling driver
divert: not allocating divert_blk for non-ethernet device sit0
eth1: no IPv6 routers present
device eth1 entered promiscuous mode
device eth1 left promiscuous mode
device eth1 entered promiscuous mode
device eth1 left promiscuous mode
device eth1 entered promiscuous mode
device eth1 left promiscuous mode
device eth1 entered promiscuous mode
device eth1 left promiscuous mode
ip_tables: (C) 2000-2002 Netfilter core team
bnx2: eth0: using MSI
bnx2: eth0 NIC Copper Link is Up, 100 Mbps half duplex
eth0: no IPv6 routers present

dmesg信息IRQ号一样：
divert: allocating divert_blk for eth0
eth0: Broadcom NetXtreme II BCM5708 1000Base-T (B2) PCI-X 64-bit 133MHz found at mem f4000000, IRQ 1
69, node addr 001d0908a98d
ACPI: PCI interrupt 0000:05:00.0[A] -> GSI 16 (level, low) -> IRQ 169
divert: allocating divert_blk for eth1
eth1: Broadcom NetXtreme II BCM5708 1000Base-T (B2) PCI-X 64-bit 133MHz found at mem f8000000, IRQ 1
69, node addr 001d0908a98b
最后查明也不是这个原因。

11，最后的原因是：
发现是启动了dell 底板管理控制器（BMC），在这里配置了一个ip地址和服务器ip地址重复。