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July 2011

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Subject:
Re: virtual network
From:
Todd And Margo Chester <[log in to unmask]>
Reply To:
Todd And Margo Chester <[log in to unmask]>
Date:
Sat, 16 Jul 2011 12:44:06 -0700
Content-Type:
text/plain
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text/plain (67 lines) 
On 07/16/2011 01:43 AM, Yasha Karant wrote:

>

> I need to see ifconfig output for eth1 and eth0, both presumably 

> physical actual NIC LAN interfaces.  I suspect that eth0.5 shares a 

> IEEE 802 MAC address with one of these physical actual NICs.  If that 

> is the case, and the network on my campus detects one MAC with two IP 

> addresses, it would disable my connection (netstat -r would never get 

> a response from the gateway).

>

> Yasha 

Hi Yasha,



    Here is a redacted "ifconfig -a" printout of the actual production

server with the Terminal Server on eth0.5 (vlan).  eth0 is the internal

network (Samba etc.); eth1 is the external, Ethernet (firewall, etc.)

facing network.



    OS= CentOS 5.6, x64



    eth0 and eth0.5 are using the same 'HWaddr"



HTH,

-T





$ ifconfig -a

eth0      Link encap:Ethernet  HWaddr 00:yy:90:11:xx:58

           inet addr:192.168.255.10  Bcast:192.168.255.255  

Mask:255.255.255.0

           inet6 addr: fe80::225:90ff:fe11:2658/64 Scope:Link

           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

           RX packets:1158619 errors:0 dropped:0 overruns:0 frame:0

           TX packets:1722958 errors:0 dropped:0 overruns:0 carrier:0

           collisions:0 txqueuelen:1000

           RX bytes:210694527 (200.9 MiB)  TX bytes:543269241 (518.1 MiB)

           Interrupt:177 Memory:fbce0000-fbd00000



eth0.5    Link encap:Ethernet  HWaddr 00:yy:90:11:xx:58

           inet addr:192.168.254.10  Bcast:192.168.254.255  

Mask:255.255.255.0

           inet6 addr: fe80::225:90ff:fe11:2658/64 Scope:Link

           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

           RX packets:0 errors:0 dropped:0 overruns:0 frame:0

           TX packets:512578 errors:0 dropped:0 overruns:0 carrier:0

           collisions:0 txqueuelen:0

           RX bytes:0 (0.0 b)  TX bytes:43628240 (41.6 MiB)



eth1      Link encap:Ethernet  HWaddr 00:yy:90:11:xx:59

           inet addr:67.xxx.yyy.zzz  Bcast:67.xxx.yyy.qqq  

Mask:255.255.255.252

           inet6 addr: xxxxxxxxxxxxxxxxxxxxxxxxx Scope:Link

           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

           RX packets:87614 errors:0 dropped:0 overruns:0 frame:0

           TX packets:71550 errors:0 dropped:0 overruns:0 carrier:0

           collisions:0 txqueuelen:1000

           RX bytes:101234059 (96.5 MiB)  TX bytes:12324311 (11.7 MiB)

           Interrupt:169 Memory:fbde0000-fbe00000



lo        Link encap:Local Loopback

           inet addr:127.0.0.1  Mask:255.0.0.0

           inet6 addr: ::1/128 Scope:Host

           UP LOOPBACK RUNNING  MTU:16436  Metric:1

           RX packets:48511 errors:0 dropped:0 overruns:0 frame:0

           TX packets:48511 errors:0 dropped:0 overruns:0 carrier:0

           collisions:0 txqueuelen:0

           RX bytes:61749859 (58.8 MiB)  TX bytes:61749859 (58.8 MiB)

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