What Do These Devices Do?

[beno]

Can you tell me what this all means? I need to understand things like:
* Through what device do such services as email, tcp, http, udp and icpm 
access my box, through which do they leave and which (if any) are used 
for internal communication?
* Also would help, what is fxp0 *traditionally* used for?
Thanks,
beno  

Jeremy C. Reed wrote:
> "ifconfig -a" should tell you about your interfaces.
>   
vr0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet 202.71.106.119 netmask 0xffffffe0 broadcast 202.71.106.127
        inet6 fe80::2e0:4cff:fee1:4ffb%vr0 prefixlen 64 scopeid 0x1
        ether 00:e0:4c:e1:4f:fb
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active
plip0: flags=108851<UP,POINTOPOINT,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet 0.0.0.0 --> 255.255.255.255 netmask 0xff000000
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
        inet 127.0.0.1 netmask 0xff000000
        inet6 ::1 prefixlen 128
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3


> And use "netstat -bi" to see if they are used too.
>   
Name    Mtu Network       Address              Ipkts Ierrs     Ibytes    
Opkts Oerrs     Obytes  Coll
vr0    1500 <Link#1>      00:e0:4c:e1:4f:fb  9355217     0 1705101091   
500970     0  250391177     0
vr0    1500 202.71.106.96 202.71.106.119      910574     -  321683093   
839022     -  441647510     -
vr0    1500 fe80:1::2e0:4 fe80:1::2e0:4cff:        0     -          
0        3     -        216     -
plip0  1500 <Link#2>                               0    10          
0        0     5          0     0
plip0  1500 0             0.0.0.0                  0     -          
0        0     -          0     -
lo0   16384 <Link#3>                          349764     0  206520178   
349764     0  206520178     0
lo0   16384 your-net      localhost.web.vi     10323     -    8207467    
10323     -    8207467     -
lo0   16384 localhost.web ::1                     84     -       
6048       84     -       6048     -
lo0   16384 fe80:3::1     fe80:3::1                0     -          
0        0     -          0     -