subinterface boogers...

when a subinterface is created there are boogers left behind, but they don't show up in show run or show start, they only show up when you show run interface;

r2620_03(config)#int fa0/0.1
r2620_03(config-subif)#encap dot1q 100
r2620_03(config-subif)#do sh run int fa0/0.1
Building configuration...

Current configuration : 60 bytes
!
interface FastEthernet0/0.1
 encapsulation dot1Q 100
end

r2620_03(config-subif)#exit
r2620_03(config)#no int fa0/0.1
% Not all config may be removed and may reappear after reactivating the sub-inte
rface

r2620_03(config)#do sh run int fa0/0.1
Building configuration...

Current configuration : 5 bytes
end
(this means my current configuration bytes)

r2620_03(config)#

i have subinterface boogers and ether crickets on me...

ppp'ing...

globally set the username as the hostname of the other router, password the same on each router, and encap ppp on each interface and you're ppp'ing...

to wit:

r2620_01#sh int s0/0
Serial0/0 is up, line protocol is up
Hardware is PowerQUICC Serial
Internet address is 30.0.0.1/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP Open
Open: IPCP, CDPCP, loopback not set
Keepalive set (10 sec)


r2620_01#sh int s0/1
Serial0/1 is up, line protocol is up
Hardware is PowerQUICC Serial
Internet address is 20.0.0.1/24
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation PPP, LCP Open
Open: IPCP, CDPCP, loopback not set
Keepalive set (10 sec)

and:

r2620_03#ping 2.2.2.2
(ping from router 3 to router 2 via router 1)
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 60/67/80 ms
r2620_03#

finally,
sh ip int will not show you the new encapsulation, sh int does...