Combine Serial Interface to Increase Link Capacity

Yesterday I mention about example to increase link capacity. Now I give example configuration about it with two Serial interface. Other way we can use Ethernet interface is EtherChannel.

Combine two Serial interface with a new logical interface is Multilink. The IP address attach in Multilink interface.

config

R2#sh run int multilink 1
interface Multilink1
 ip address 192.168.0.2 255.255.255.252
 ppp multilink
 multilink-group 1
end

R2#sh run int serial 1/1
interface Serial1/1
 no ip address
 encapsulation ppp
 serial restart_delay 0
 ppp multilink
 multilink-group 1
end

R2#sh run int serial 1/2
interface Serial1/2
 no ip address
 encapsulation ppp
 serial restart_delay 0
 ppp multilink
 multilink-group 1
end

Monitor & Verify

R2#sh int multilink 1
Multilink1 is up, line protocol is up 
  Hardware is multilink group interface
  Internet address is 192.168.0.2/30
  MTU 1500 bytes, BW 3088 Kbit, DLY 100000 usec, 
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation PPP, LCP Open, multilink Open
  Open: CDPCP, IPCP, loopback not set
  DTR is pulsed for 2 seconds on reset
  Last input 00:00:37, output never, output hang never
  Last clearing of "show interface" counters 00:01:38
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     8 packets input, 866 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     10 packets output, 876 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions
     
R2#sh int s1/1
Serial1/1 is up, line protocol is up 
  Hardware is M4T
  MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, 
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation PPP, LCP Open, multilink Open, crc 16, loopback not set
  Restart-Delay is 0 secs
  Last input 00:00:42, output 00:00:09, output hang never
  Last clearing of "show interface" counters 00:01:22
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: weighted fair  [suspended, using FIFO]
  FIFO output queue 0/40, 0 drops
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     30 packets input, 1722 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     27 packets output, 769 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions     DCD=up  DSR=up  DTR=up  RTS=up  CTS=up

R2#sh ppp ?
  bap        BAP parameters and statistics
  mppe       MPPE statistics
  multilink  Multilink PPP bundle information
  queues     Event Manager request queues

R2#sh ppp multilink l?
% Unrecognized command
R2#sh ppp multilink ?
  interface  Show information for this MLP bundle only
  |          Output modifiers
  

R2#sh ppp multilink 

Multilink1, bundle name is R1
  Bundle up for 00:01:25, 1/255 load
  Receive buffer limit 24384 bytes, frag timeout 1000 ms
    0/0 fragments/bytes in reassembly list
    0 lost fragments, 0 reordered
    0/0 discarded fragments/bytes, 0 lost received
    0xC received sequence, 0xC sent sequence
  Member links: 2 active, 0 inactive (max not set, min not set)
    Se1/1, since 00:01:29
    Se1/2, since 00:01:14