32.Frame-Relay [ multipoint]

<Multipoint Frame-rely>

• Subinterface를 Multi Access Network의 Interface 처럼 작동 시킨다.
• 하나의 subnet을 필요로 한다

.⇒ 동적라우팅할때 주의가 필요하다.

 

 

interface s1/0.123 multipoint

no frame-relay inverse-arp ⇒ 미리 자동으로 주소를 받아오는 arp mapping을 막아준다.

ip add 1.1.12.1 255.255.255.0

no ip split-horizon

frame-relay map ip 1.1.12.2 102 broadcast

frame-relay map ip 1.1.12.3

103 broadcast

 

Router(config)# interface Serial1/0.123 multipoint
Router(config-subif)#frame-relay map ip 1.1.123.1 302 broadcast

<부분메시 구조>

= > 하나의 인터페이스에 여러개가 연결되어 있는 것을 부분메시 구조라고 한다.

= > 다른 말로 hub and spoke 구조라고 합니다.

 

⇒ 위의 그림을 펼쳐서 보게되면 4개의 홉을 가진

 

라우터 작성

<FR>

interface Serial1/0

no ip address encapsulation frame-relay

frame-relay intf-type dce

frame-relay route 102 interface Serial1/1 201

!

interface Serial1/1

no ip address encapsulation frame-relay

frame-relay intf-type dce

frame-relay route 201 interface Serial1/0 102

frame-relay route 203 interface Serial1/2 302

!

interface Serial1/2

no ip address encapsulation

frame-relay serial restart-delay 0

frame-relay intf-type dce

frame-relay route 302 interface Serial1/1 203

frame-relay route 304 interface Serial1/3 403

!

interface Serial1/3

no ip address encapsulation frame-relay

frame-relay intf-type dce

frame-relay route 403 interface Serial1/2 304

 

<R1>

interface Serial1/0

no ip address encapsulation frame-relay

 

interface Serial1/0.123 point-to-point

ip address 1.1.123.1 255.255.255.0

no ip split-horizon frame-relay interface-dlci 102

 

<R2>

interface Serial1/0

no ip address encapsulation frame-relay

 

interface Serial1/0.123 multipoint

ip address 1.1.123.2 255.255.255.0

no ip split-horizon

frame-relay map ip 1.1.123.3 203 broadcast

frame-relay map ip 1.1.123.1 201 broadcast

no frame-relay inverse-arp

 

<R3>

interface Serial1/0

no ip address encapsulation frame-relay

 

interface Serial1/0.34 point-to-point

ip address 1.1.34.3 255.255.255.0

frame-relay interface-dlci 304

 

interface Serial1/0.123 multipoint

ip address 1.1.123.3 255.255.255.0

no ip split-horizon

frame-relay map ip 1.1.123.1 302 broadcast

frame-relay map ip 1.1.123.2 302 broadcast

no frame-relay inverse-arp

<R4>

interface Serial1/0

no ip address encapsulation frame-relay

 

interface Serial1/0.34 point-to-point

ip address 1.1.34.4 255.255.255.0

frame-relay interface-dlci 403

 

ip split horizon ⇒ looping을 방지하기위한 명령어 기본적으로 적혀있다.

세번째 줄에 non_broadcast를 확인할 수 있다.

중간에 위치한 R2가 무조건 반장(DR)이 되도록 우선순위를 바꿔준다.