D-H,appy

# 패켓 스위칭(Packet Switching)

 - 라우팅(Routing) : Layer 3 계층 데이터 전송 처리, Layer 3 계층 주소 사용(IP 주소)
 - 스위칭(Switching) : Layer 2 계층 데이터 전송 처리, Layer 2 계층 주소 사용(MAC/DLCI 주소)

 - 패켓(Packet) : Layer 3 계층 데이터 단위
 - 프레임(Frame) : Layer 2 계층 데이터 단위

# Frame-Relay 패켓 스위칭망 (Ex : LG 데이콤)

 - 하나의 본사에 여러개의 지사와 WAN 환경을 구성하며, 비용 절감을 위해서 사용한다.

 - ARP : Layer 3 계층 주소(IP)를 이용하여 Layer 2 계층 주소(MAC)를 학습하는 기능
 - Inverse-ARP : Layer 2 계층 주소(DLCI)를 이용하여 Layer 3 계층 주소(IP)를 학습하는 기능

1) Frame-Relay 동적 기본 설정(Inverse-ARP 사용)

R1(config)# int s1/3
R1(config-if)# ip address x.x.123.1 255.255.255.0
R1(config-if)# encapsulation frame-relay
R1(config-if)# frame-relay inverse-arp <- 기본 설정되어 있기때문에 설정 불필요
R1(config-if)# no shutdown

R2(config)# int s1/3
R2(config-if)# ip address x.x.123.2 255.255.255.0
R2(config-if)# encapsulation frame-relay
R2(config-if)# frame-relay inverse-arp <- 기본 설정되어 있기때문에 설정 불필요
R2(config-if)# no shutdown

R3(config)# int s1/3
R3(config-if)# ip address x.x.123.3 255.255.255.0
R3(config-if)# encapsulation frame-relay
R3(config-if)# frame-relay inverse-arp <- 기본 설정되어 있기때문에 설정 불필요
R3(config-if)# no shutdown

 - R1,R2,R3에서 'show frame-relay map' 명령어를 이용하여 학습한 Frame-Relay MAP 확인

R1# show frame-relay map
Serial1/3 (up): ip 13.13.123.2 dlci 102(0x66,0x1860), dynamic,
              broadcast,
              CISCO, status defined, active
Serial1/3 (up): ip 13.13.123.3 dlci 103(0x67,0x1870), dynamic,
              broadcast,
              CISCO, status defined, active

R2# show frame-relay map
Serial1/3 (up): ip 13.13.123.1 dlci 201(0xC9,0x3090), dynamic,
              broadcast,
              CISCO, status defined, active
Serial1/3 (up): ip 13.13.123.3 dlci 203(0xCB,0x30B0), dynamic,
              broadcast,
              CISCO, status defined, active

R3# show frame-relay map
Serial1/3 (up): ip 13.13.123.1 dlci 301(0x12D,0x48D0), dynamic,
              broadcast,
              CISCO, status defined, active
Serial1/3 (up): ip 13.13.123.2 dlci 302(0x12E,0x48E0), dynamic,
              broadcast,
              CISCO, status defined, active

2) Frame-Relay 정적 매핑 설정

 Hub 라우터 : R1
 Spoke 라우터 : R2&R3

R1(config)# int s1/3
R1(config-if)# ip address x.x.123.1 255.255.255.0
R1(config-if)# encapsulation frame-relay
R1(config-if)# no frame-relay inverse-arp
R1(config-if)# frame-relay map ip x.x.123.2 102 broadcast
R1(config-if)# frame-relay map ip x.x.123.3 103 broadcast
R1(config-if)# no shutdown

R2(config)# int s1/3
R2(config-if)# ip address x.x.123.2 255.255.255.0
R2(config-if)# encapsulation frame-relay
R2(config-if)# no frame-relay inverse-arp
R2(config-if)# frame-relay map ip x.x.123.1 201 broadcast
R2(config-if)# frame-relay map ip x.x.123.3 201 broadcast
R2(config-if)# no shutdown

R3(config)# int s1/3
R3(config-if)# ip address x.x.123.3 255.255.255.0
R3(config-if)# encapsulation frame-relay
R3(config-if)# no frame-relay inverse-arp
R3(config-if)# frame-relay map ip x.x.123.1 301 broadcast
R3(config-if)# frame-relay map ip x.x.123.2 301 broadcast
R3(config-if)# no shutdown

 - R1,R2,R3에서 'show frame-relay map' 명령어를 이용하여 학습한 Frame-Relay MAP 확인

R1#show frame-relay map
Serial1/3 (up): ip 13.13.123.2 dlci 102(0x66,0x1860), static,
              broadcast,
              CISCO, status defined, active
Serial1/3 (up): ip 13.13.123.3 dlci 103(0x67,0x1870), static,
              broadcast,
              CISCO, status defined, active

R2#show frame-relay map
Serial1/3 (up): ip 13.13.123.1 dlci 201(0xC9,0x3090), static,
              broadcast,
              CISCO, status defined, active
Serial1/3 (up): ip 13.13.123.3 dlci 201(0xC9,0x3090), static,
              broadcast,
              CISCO, status defined, active

R3#show frame-relay map
Serial1/3 (up): ip 13.13.123.1 dlci 301(0x12D,0x48D0), static,
              broadcast,
              CISCO, status defined, active
Serial1/3 (up): ip 13.13.123.2 dlci 301(0x12D,0x48D0), static,
              broadcast,
              CISCO, status defined, active

[참고] Frame-Relay NBMA 환경과 Distance Vector 라우팅 프로토콜(RIPv1/v2, IGRP, EIGRP) 관계

R1,R2,R3(config)# router rip
R1,R2,R3(config-router)# version 2
R1,R2,R3(config-router)# no auto-summary
R1,R2,R3(config-router)# network x.0.0.0

R1,R2,R3# show ip route

R1#show ip interface s1/3
Serial1/3 is up, line protocol is up
  Internet address is 13.13.123.1/24
  Broadcast address is 255.255.255.255
  Address determined by setup command
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is disabled
  Multicast reserved groups joined: 224.0.0.9
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Local Proxy ARP is disabled
  Security level is default
  Split horizon is disabled <- 자동으로 Disable 상태이다.

 - Frame-Relay를 주인터페이스에 설정하면 자동으로 Split-Horizon을 Disable하여 Distance Vector
   라우팅 업데이트가 가능하도록 한다.

 - Router(config-if)# ip split-horizon
 - Router(config-if)# no ip split-horizon

R1,R2,R3(config)# default int s1/3
R1,R2,R3(config)# int s1/3
R1,R2,R3(config-if)# shutdown

3. Sub-Interface를 이용한 'Split-Horizon' 이슈 문제 해결 및 확장성 제공하는 설정

Router(config)# int s1/3
Router(config-if)# encapsulation frame-relay
Router(config-if)# no shutdown
Router(config-if)# exit
Router(config)#
Router(config)# int s1/3.?
  <0-4294967295>  Serial interface number <- 서브 인터페이스 범위(32bit)

Router(config)# int s1/3.12 ?
  multipoint        Treat as a multipoint link <- NBMA 네트워크 환경
  point-to-point  Treat as a point-to-point link <- 점 대 점 네트워크 환경

[LAB 20 : Frame-Relay Point-to-Point - Dynamips -]

 1) 서브-인터페이스를 이용한 Point-to-Point 환경 설정 (점-대-점 환경)

 - Hub 라우터 : R1

 - Spoke 라우터 : R2(S1/3.12 : x.x.12.2/24)
                        R3(S1/3.13 : x.x.13.3/24)

 R1-R2 서브넷 : x.x.12.y/24
 R2-R3 서브넷 : x.x.13.y/24

R1(config)# int s1/3
R1(config-if)# encapsulation frame-relay
R1(config-if)# no shutdown
R1(config-if)# int s1/3.12 point-to-point <- R2와 점대점 환경 서브 인터페이스
R1(config-subif)# ip address x.x.12.1 255.255.255.0
R1(config-subif)# frame-relay interface-dlci 102
R1(config-subif)# int s1/3.13 point-to-point <- R3와 점대점 환경 서브 인터페이스
R1(config-subif)# ip address x.x.13.1 255.255.255.0
R1(config-subif)# frame-relay interface-dlci 103

R2(config)# int s1/3
R2(config-if)# encapsulation frame-relay
R2(config-if)# no shutdown
R2(config-if)# int s1/3.12 point-to-point <- R1과 점대점 환경 서브 인터페이스
R2(config-subif)# ip address x.x.12.2 255.255.255.0
R2(config-subif)# frame-relay interface-dlci 201

R3(config)# int s1/3
R3(config-if)# encapsulation frame-relay
R3(config-if)# no shutdown
R3(config-if)# int s1/3.13 point-to-point <- R1과 점대점 환경 서브 인터페이스
R3(config-subif)# ip address x.x.13.3 255.255.255.0
R3(config-subif)# frame-relay interface-dlci 301

R1# show ip interface s1/3.12

R1(config)# no int s1/3.12
R1(config)# no int s1/3.13

R2(config)# no int s1/3.12

R3(config)# no int s1/3.13

 - 서브 인터페이스는 삭제할수 있으나, 다시 생성할 경우 해당 Link-Type으로 복구가 된다.

Router(config)# no int s1/3.12
Not all config may be removed and may reappear after reactivating the sub-interface

Router(config)# int s1/3.12 multipoint
% Warning:  cannot change link type

 - 완전 삭제를 하기 위해서는 서브 인터페이스를 삭제한 이후, 설정 내용을 NVRAM에 저장하고
    라우터를 reload(재부팅)를 실시한다.

2) 서브-인터페이스를 이용한 Multipoint 환경 설정(NBMA 환경) <- 정적 매핑

 - Hub 라우터 : R1(S1/3.123 : x.x.123.1/24)

 - Spoke 라우터 : R2(S1/3.123 : x.x.123.2/24)
                       R3(S1/3.123 : x.x.123.3/24)

R1(config)# in s1/3
R1(config-if)# encapsulation frame-relay
R1(config-if)# no frame-relay inverse-arp
R1(config-if)# no shutdown
R1(config-if)# int s1/3.123 multipoint
R1(config-subif)# ip address x.x.123.1 255.255.255.0
R1(config-subif)# frame-relay map ip x.x.123.2 102 broadcast
R1(config-subif)# frame-relay map ip x.x.123.3 103 broadcast
R1(config-subif)# no ip split-horizon

R2(config)# int s1/3
R2(config-if)# encapsulation frame-relay
R2(config-if)# no frame-relay inverse-arp
R2(config-if)# no shutdown
R2(config-if)# int s1/3.123 multipoint
R2(config-subif)# ip address x.x.123.2 255.255.255.0
R2(config-subif)# frame-relay map ip x.x.123.1 201 broadcast
R2(config-subif)# frame-relay map ip x.x.123.3 201 broadcast

R3(config)# int s1/3
R3(config-if)# encapsulation frame-relay
R3(config-if)# no frame-relay inverse-arp
R3(config-if)# no shutdown
R3(config-if)# int s1/3.123 multipoint
R3(config-subif)# ip address x.x.123.3 255.255.255.0
R3(config-subif)# frame-relay map ip x.x.123.1 301 broadcast
R3(config-subif)# frame-relay map ip x.x.123.2 301 broadcast

 - R1,R2,R3에서 'show frame-relay map' 명령어를 이용하여 Frame-Relay Map 정보 확인

R1# show frame-relay map
Serial1/3.123 (up): ip 13.13.123.2 dlci 102(0x66,0x1860), static,
              broadcast,
              CISCO, status defined, active
Serial1/3.123 (up): ip 13.13.123.3 dlci 103(0x67,0x1870), static,
              broadcast,
              CISCO, status defined, active

R2# show frame-relay map
Serial1/3.123 (up): ip 13.13.123.1 dlci 201(0xC9,0x3090), static,
              broadcast,
              CISCO, status defined, active
Serial1/3.123 (up): ip 13.13.123.3 dlci 201(0xC9,0x3090), static,
              broadcast,
              CISCO, status defined, active

R3# show frame-relay map
Serial1/3.123 (up): ip 13.13.123.1 dlci 301(0x12D,0x48D0), static,
              broadcast,
              CISCO, status defined, active
Serial1/3.123 (up): ip 13.13.123.2 dlci 301(0x12D,0x48D0), static,
              broadcast,
              CISCO, status defined, active

 - R1,R2,R3에서 'show ip route' 명령어를 실시하여 RIPv2 업데이트 정보 확인
 - R1,R2,R3에서 Ping 테스트 실시

R1# ping x.x.2.1
R1# ping x.x.3.1

R2# ping x.x.1.1
R2# ping x.x.3.1

R3# ping x.x.1.1
R3# ping x.x.2.1