Problems caused by interface encapsulation and ing

Interfaces in the LAN encapsulate the Ethernet type.

In the WAN, the interface is generally a serial port encapsulation of ppp hdlc snip Frame-Realy

ARP is used for Ethernet, And it communicates with MAC addresses.

If both sides of the serial port are PPP or HDLC, the two layers will be connected, and frame relay uses DLCI.

 

(N.1) s0 \ 0 ports of RI \ R2 are blocked by PPP R1s0 \ 0 ip address 192.168.1.1 255.255.255.0

R2s0 \ 0 ip address 172.16.1.1 255.255.255.0

R1 # ping 172.16.1.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/93/160 MS

R1 # show io route

Gateway of last resort is not set

172.16.0.0/32 is subnetted, 1 subnets
C 172.16.1.1 is directly connected, Serial0/0
C 192.168.1.0/24 is directly connected, Serial0/0

(N.2) both sides block HDLC

R1 # ping 172.16.1.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

R1 # show ip route (the rest remain unchanged)

Gateway of last resort is not set

C 192.168.1.0/24 is directly connected, Serial0/0

(N.3) both sides encapsulate HDLC

R1 address: 172.16.1.1 255.255.255.0 R2 address: 172.16.2.2 255.255.255.0

R1 # ping 172.16.2.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.2.2, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

(N.4) both sides block HDLC

R1 ip address 172.16.1.1 255.255.255.0 R2 ip address 172.16.1.2 255.255.255.0.0

R1 # ping 172.16.1.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/95/196 MS

R1 # show ip route

172.16.0.0/24 is subnetted, 1 subnets
C 172.16.1.0 is directly connected, Serial0/0

 

(N.1) R1 ip address 10.1.1.1 255.255.255.0 R2 ip addrss 10.1.1.2 255.255.255.0

R1 ping R2 !!!!!

(N.2) R1 10.1.1.1 255.255.255.0 R2 10.2.2.2 255.255.255.0

R1 ping R2 failed

(N.3) R1 10.1.1.1 255.255.255.0 R2 10.2.2.2 255.255.255.0

R1 (config) # no ip routing

R1 # ping 10.2.2.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.2.2.2, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

Capture a package

When R1 disables the routing function, it sends an ARP request to PING different CIDR blocks, but R2 does not disable the routing function. It checks that the route table does not have a route to 10.1.1.1.

After we disable the routing function of R2.

R1 # ping 10.2.2.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.2.2.2, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 12/67/156 MS

 

 

 

This article is from the "Network Technology" blog