Frame Relay訊框中繼
Frame
Relay的實體線路架構,由各區域辦公室,申請區域專線連接到當地ISP最近的機房,這條區域專線的速度就是Local Access Rate,也就是該線路能夠乘載的最高頻寬。
CIR(Committed
Information Rate)保證資料傳輸速率 CIR是ISP業者保證可以傳送的速度。
Frame Relay的封裝
1.Frame Relay Cisco:Cisco專屬協定。
2.Frame Relay IEFT:標準協定。
Virtual Circuit(虛擬電路)
1.固接式(PVC)
2.交換式(SVC):當有資料要傳遞時才建立,傳遞完成後就中斷。
DLCI(Data Link Connection Identifier)資料連結連線識別碼
建立PVC時,使用DLCI來識別連接點,DLCI由ISP業者提供。
LMI(Local Manager Interface)區域管理介面
Router到所連接Frame Relay交換機之間所用的訊號標準,Router可藉由LMI得知整個線路狀況。
格式:(由ISP業者決定)
1.Cisco
2.ANSI
3.Q.933A
Inverse
ARP
建立PVC時,可以手動指定DLCI與IP對應關係,也可以使用Inverse ARP讓Router自動搜尋PVC另一端的設備位置。
FECN(Forward Explicit Congestion Notification)
FECN是Frame Relay封包表頭內的一個位元。當Router(DTE)發送Frame Relay封包出去時,如果網路發生雍塞,Frame Relay交換機(DCE)就會把FECN的值設成1。當目的端設備看到這個FECN的值是1時,就知道網路雍塞狀況。Router(DTE)設備就可以針對網路雍塞狀況做出處置動作(如降低傳送速率)。
BECN(Backward Explicit Congestion Notification)
BECN也是Frame Relay封包表頭內的一個位元。當Frame Relay交換機(DCE)以反方向發送回給Router(DTE),而FECN的值為1的時候,Frame Relay交換機(DCE)就會把BECN的值也設成1,來告訴來源端的DTE設備,Frame Relay發生壅塞的狀況,來源端的Router(DTE)設備就會針對網路雍塞做出處置裝置。
<點對點Frame Relay設定>
Relay的實體線路架構,由各區域辦公室,申請區域專線連接到當地ISP最近的機房,這條區域專線的速度就是Local Access Rate,也就是該線路能夠乘載的最高頻寬。
CIR(Committed
Information Rate)保證資料傳輸速率 CIR是ISP業者保證可以傳送的速度。
Frame Relay的封裝
1.Frame Relay Cisco:Cisco專屬協定。
2.Frame Relay IEFT:標準協定。
Virtual Circuit(虛擬電路)
1.固接式(PVC)
2.交換式(SVC):當有資料要傳遞時才建立,傳遞完成後就中斷。
DLCI(Data Link Connection Identifier)資料連結連線識別碼
建立PVC時,使用DLCI來識別連接點,DLCI由ISP業者提供。
LMI(Local Manager Interface)區域管理介面
Router到所連接Frame Relay交換機之間所用的訊號標準,Router可藉由LMI得知整個線路狀況。
格式:(由ISP業者決定)
1.Cisco
2.ANSI
3.Q.933A
Inverse
ARP
建立PVC時,可以手動指定DLCI與IP對應關係,也可以使用Inverse ARP讓Router自動搜尋PVC另一端的設備位置。
FECN(Forward Explicit Congestion Notification)
FECN是Frame Relay封包表頭內的一個位元。當Router(DTE)發送Frame Relay封包出去時,如果網路發生雍塞,Frame Relay交換機(DCE)就會把FECN的值設成1。當目的端設備看到這個FECN的值是1時,就知道網路雍塞狀況。Router(DTE)設備就可以針對網路雍塞狀況做出處置動作(如降低傳送速率)。
BECN(Backward Explicit Congestion Notification)
BECN也是Frame Relay封包表頭內的一個位元。當Frame Relay交換機(DCE)以反方向發送回給Router(DTE),而FECN的值為1的時候,Frame Relay交換機(DCE)就會把BECN的值也設成1,來告訴來源端的DTE設備,Frame Relay發生壅塞的狀況,來源端的Router(DTE)設備就會針對網路雍塞做出處置裝置。
<點對點Frame Relay設定>
1.LMI使用Cisco格式
2.Router-1的DLCI=100
3.Router-2的DLCI=200
Router-1(config)#int
serial 1/0
Router-1(config-if)#ip address 10.1.1.1 255.255.255.0
Router-1(config-if)#encapsulation frame-relay ? ietf Use
RFC1490/RFC2427 encapsulation
<cr>
Router-1(config-if)#encapsulation frame-relay (即為Frame Relay Cisco封裝)
Router-1(config-if)#frame-relay ?
interface-dlci Define a DLCI on an interface/subinterface
lmi-type Use CISCO-ANSI-CCITT type LMI
map Map a protocol address to a DLCI address
Router-1(config-if)#frame-relay lmi-type ? ansi
cisco
q933a
Router-1(config-if)#frame-relay lmi-type cisco
Router-1(config-if)#frame-relay interface-dlci ?
<16-1007> Define a switched or locally terminated DLCI
Router-1(config-if)#frame-relay interface-dlci 100
Router-1(config-if)#frame-relay map ip 10.1.1.2 ?
<16-1007> DLCI
Router-1(config-if)#frame-relay map ip 10.1.1.2 100 (告知DLCI 100可以通到10.1.1.2)
Router-1(config-if)#no sh
Router-2(config)#int serial 1/0
Router-2(config-if)#ip address 10.1.1.2 255.255.255.0
Router-2(config-if)#encapsulation frame-relay
Router-2(config-if)#frame-relay lmi-type cisco
Router-2(config-if)#frame-relay interface-dlci 200
Router-2(config-if)#frame-relay map ip 10.1.1.1 200 (告知DLCI 200可以通到10.1.1.1)
Router-2(config-if)#no sh
Router-1#sh run
Building configuration...!
interface Serial1/0 ip address 10.1.1.1 255.255.255.0 encapsulation frame-relay
frame-relay map ip 10.1.1.2 100 frame-relay interface-dlci 100
Router-1#sh interfaces serial 1/0
Serial1/0 is up, line protocol is up (connected)
Hardware is HD64570
Internet address is 10.1.1.1/24
MTU 1500 bytes, BW 128 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation
Frame Relay,
loopback not set, keepalive set (10 sec)
LMI enq sent 110, LMI stat recvd 109, LMI upd recvd 0, DTE LMI up
LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0
LMI DLCI 1023 LMI type is CISCO frame relay DTE
Broadcast queue 0/64, broadcasts sent/dropped 0/0, interface broadcasts 0
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
<點對點Frame
Relay設定-IETF封裝>
2.Router-1的DLCI=100
3.Router-2的DLCI=200
Router-1(config)#int
serial 1/0
Router-1(config-if)#ip address 10.1.1.1 255.255.255.0
Router-1(config-if)#encapsulation frame-relay ? ietf Use
RFC1490/RFC2427 encapsulation
<cr>
Router-1(config-if)#encapsulation frame-relay (即為Frame Relay Cisco封裝)
Router-1(config-if)#frame-relay ?
interface-dlci Define a DLCI on an interface/subinterface
lmi-type Use CISCO-ANSI-CCITT type LMI
map Map a protocol address to a DLCI address
Router-1(config-if)#frame-relay lmi-type ? ansi
cisco
q933a
Router-1(config-if)#frame-relay lmi-type cisco
Router-1(config-if)#frame-relay interface-dlci ?
<16-1007> Define a switched or locally terminated DLCI
Router-1(config-if)#frame-relay interface-dlci 100
Router-1(config-if)#frame-relay map ip 10.1.1.2 ?
<16-1007> DLCI
Router-1(config-if)#frame-relay map ip 10.1.1.2 100 (告知DLCI 100可以通到10.1.1.2)
Router-1(config-if)#no sh
Router-2(config)#int serial 1/0
Router-2(config-if)#ip address 10.1.1.2 255.255.255.0
Router-2(config-if)#encapsulation frame-relay
Router-2(config-if)#frame-relay lmi-type cisco
Router-2(config-if)#frame-relay interface-dlci 200
Router-2(config-if)#frame-relay map ip 10.1.1.1 200 (告知DLCI 200可以通到10.1.1.1)
Router-2(config-if)#no sh
Router-1#sh run
Building configuration...!
interface Serial1/0 ip address 10.1.1.1 255.255.255.0 encapsulation frame-relay
frame-relay map ip 10.1.1.2 100 frame-relay interface-dlci 100
Router-1#sh interfaces serial 1/0
Serial1/0 is up, line protocol is up (connected)
Hardware is HD64570
Internet address is 10.1.1.1/24
MTU 1500 bytes, BW 128 Kbit, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation
Frame Relay,
loopback not set, keepalive set (10 sec)
LMI enq sent 110, LMI stat recvd 109, LMI upd recvd 0, DTE LMI up
LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0
LMI DLCI 1023 LMI type is CISCO frame relay DTE
Broadcast queue 0/64, broadcasts sent/dropped 0/0, interface broadcasts 0
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
<點對點Frame
Relay設定-IETF封裝>
1.Encapsulation:IETF
2.LMI:Q933a
3.Router-1 DLCI=110
4.Router-2
DLCI=210
Router-1(config)#int serial 1/0
Router-1(config-if)#ip address 10.1.1.1 255.255.255.0
Router-1(config-if)#encapsulation frame-relay ietf
Router-1(config-if)#frame-relay lmi-type q933a
Router-1(config-if)#frame-relay interface-dlci 110
Router-1(config-if)#frame-relay map ip 10.1.1.2 110
Router-1(config-if)#no sh
Router-2(config)#int serial 1/0
Router-2(config-if)#ip address 10.1.1.2 255.255.255.0
Router-2(config-if)#encapsulation frame-relay ietf
Router-2(config-if)#frame-relay lmi-type q933a
Router-2(config-if)#frame-relay interface-dlci 210
Router-2(config-if)#frame-relay map ip 10.1.1.1 210
Router-2(config-if)#no sh
<多點Frame Relay連線>(點對點模式).
2.LMI:Q933a
3.Router-1 DLCI=110
4.Router-2
DLCI=210
Router-1(config)#int serial 1/0
Router-1(config-if)#ip address 10.1.1.1 255.255.255.0
Router-1(config-if)#encapsulation frame-relay ietf
Router-1(config-if)#frame-relay lmi-type q933a
Router-1(config-if)#frame-relay interface-dlci 110
Router-1(config-if)#frame-relay map ip 10.1.1.2 110
Router-1(config-if)#no sh
Router-2(config)#int serial 1/0
Router-2(config-if)#ip address 10.1.1.2 255.255.255.0
Router-2(config-if)#encapsulation frame-relay ietf
Router-2(config-if)#frame-relay lmi-type q933a
Router-2(config-if)#frame-relay interface-dlci 210
Router-2(config-if)#frame-relay map ip 10.1.1.1 210
Router-2(config-if)#no sh
<多點Frame Relay連線>(點對點模式).
可以在一個實體介面中,建立出多個虛擬子介面,給予不同的IP與不同的相關設定。用子介面建立Frame Relay連線有兩種模式,一種是Point to Point(點對點模式),另一種是MultiPoint(多點模式)。實體介面只設定封裝協定,不指定IP。
Router-1
S
1/0.130 10.1.1.1 130
S
1/0.120 10.1.2.1 120
Router-2
S
1/0.210 10.1.2.2 210
S
1/0.230 10.1.3.1 230
Router-3
S
1/0.310 10.1.1.2 310
S
1/0.320 10.1.3.2 320
Router-1(config)#int serial 1/0
Router-1(config-if)#encapsulation frame-relay
Router-1(config-if)#no sh
Router-1(config-if)#exit
Router-1(config)#int serial 1/0.120 point-to-point
Router-1(config-subif)#ip address 10.1.2.1 255.255.255.0
Router-1(config-subif)#frame-relay interface-dlci 120
Router-1(config-subif)#exit
Router-1(config)#int serial 1/0.130 point-to-point
Router-1(config-subif)#ip address 10.1.1.1 255.255.255.0
Router-1(config-subif)#frame-relay interface-dlci 130
Router-1(config)#do sh run
Building configuration...!
!
interface
Serial1/0
no
ip address
encapsulation
frame-relay
!
interface
Serial1/0.120 point-to-point
ip
address 10.1.2.1 255.255.255.0
frame-relay
interface-dlci 120
!
interface
Serial1/0.130 point-to-point
ip
address 10.1.1.1 255.255.255.0
frame-relay
interface-dlci 130
!
Router-1(config)#router rip (設定路由)
Router-1(config-router)#network 10.0.0.0
同方式,設定Router-2、Router-3
<多點Frame
Relay連線>(多點模式)
Router-1
S
1/0.130 10.1.1.1 130
S
1/0.120 10.1.2.1 120
Router-2
S
1/0.210 10.1.2.2 210
S
1/0.230 10.1.3.1 230
Router-3
S
1/0.310 10.1.1.2 310
S
1/0.320 10.1.3.2 320
Router-1(config)#int serial 1/0
Router-1(config-if)#encapsulation frame-relay
Router-1(config-if)#no sh
Router-1(config-if)#exit
Router-1(config)#int serial 1/0.120 point-to-point
Router-1(config-subif)#ip address 10.1.2.1 255.255.255.0
Router-1(config-subif)#frame-relay interface-dlci 120
Router-1(config-subif)#exit
Router-1(config)#int serial 1/0.130 point-to-point
Router-1(config-subif)#ip address 10.1.1.1 255.255.255.0
Router-1(config-subif)#frame-relay interface-dlci 130
Router-1(config)#do sh run
Building configuration...!
!
interface
Serial1/0
no
ip address
encapsulation
frame-relay
!
interface
Serial1/0.120 point-to-point
ip
address 10.1.2.1 255.255.255.0
frame-relay
interface-dlci 120
!
interface
Serial1/0.130 point-to-point
ip
address 10.1.1.1 255.255.255.0
frame-relay
interface-dlci 130
!
Router-1(config)#router rip (設定路由)
Router-1(config-router)#network 10.0.0.0
同方式,設定Router-2、Router-3
<多點Frame
Relay連線>(多點模式)
Router(config)#int
serial 1/0
Router(config-if)#encapsulation
frame-relay
Router(config-if)#no
sh
Router(config-if)#exit
Router(config)#int serial 1/0.2 multipoint
Router(config-subif)#ip address 10.1.1.1 255.255.255.0
Router(config-subif)#frame-relay map ip 10.1.1.3 130
Router(config-subif)#frame-relay map ip 10.1.1.2 120
Router(config-subif)#frame-relay interface-dlci 120
Router(config-subif)#frame-relay interface-dlci 130
Router(config-subif)#do sh run
Building
configuration...
Current
configuration : 891 bytes
!
!
interface
Serial1/0
no
ip address
encapsulation
frame-relay
!
interface
Serial1/0.2 multipoint
ip
address 10.1.1.1 255.255.255.0
frame-relay
map ip 10.1.1.3 130
frame-relay
map ip 10.1.1.2 120
frame-relay
interface-dlci 120
frame-relay
interface-dlci 130
!
同方式設定,Router-2、Router-3
Frame Relay檢修指令
1.Sh
Frame-Relay LMI:檢視Router介面與Frame Relay交換機LMI封裝協定與流量統計數據。
Router#sh frame-relay lmi
LMI
Statistics for interface Serial1/0 (Frame Relay DTE) LMI TYPE = CISCO
Invalid
Unnumbered info 0 Invalid Prot Disc 0
Invalid
dummy Call Ref 0 Invalid Msg Type 0
Invalid
Status Message 0 Invalid Lock Shift 0
Invalid
Information ID 0 Invalid Report IE Len 0
Invalid
Report Request 0 Invalid Keep IE Len 0
Num
Status Enq. Sent 169 Num Status msgs Rcvd 168
Num
Update Status Rcvd 0 Num Status Timeouts 16
LMI
Statistics for interface Serial1/0.2 (Frame Relay DTE) LMI TYPE =
CISCO
Invalid
Unnumbered info 0 Invalid Prot Disc 0
Invalid
dummy Call Ref 0 Invalid Msg Type 0
Invalid
Status Message 0 Invalid Lock Shift 0
Invalid
Information ID 0 Invalid Report IE Len 0
Invalid
Report Request 0 Invalid Keep IE Len 0
Num
Status Enq. Sent 0 Num Status msgs Rcvd 0
Num
Update Status Rcvd 0 Num Status Timeouts 16
2.Sh Frame-Relay PVC:檢視PVC與DLCI編碼,每條PVC的連線流量統計數據。
Router#sh frame-relay pvc
PVC
Statistics for interface Serial1/0 (Frame Relay DTE)
DLCI = 120, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1/0.2
input
pkts 14055 output pkts 32795 in
bytes 1096228
out
bytes 6216155 dropped pkts 0
in FECN pkts 0
in
BECN pkts 0 out FECN pkts 0
out BECN pkts 0
in
DE pkts 0 out DE pkts 0
out
bcast pkts 32795 out bcast bytes 6216155
DLCI
= 130, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE =
Serial1/0.2
input
pkts 14055 output pkts 32795 in
bytes 1096228
out
bytes 6216155 dropped pkts 0
in FECN pkts 0
in
BECN pkts 0 out FECN pkts 0
out BECN pkts 0
in
DE pkts 0 out DE pkts 0
out
bcast pkts 32795 out bcast bytes 6216155
3.Sh Frame-Relay MAP:檢視IP與DLCI編碼的對應關係。
Router#sh frame-relay map
Serial1/0.2
(up): ip 10.1.1.3 dlci 130, static, CISCO, status defined, active
Serial1/0.2
(up): ip 10.1.1.2 dlci 120, static, CISCO, status defined, active
4.Debug Frame-Relay LMI:可檢視Router介面與ISP
Frame Relay交換機的溝通訊息,協助我們觀察Router與交換機是否正確地交換LMI資訊。
Router#no debug frame-relay lmi
Frame
Relay LMI debugging is off
Displaying
all Frame Relay LMI data
Router#debug frame-relay lmi
Frame
Relay LMI debugging is on
Displaying
all Frame Relay LMI data
Serial1/0(out):
StEnq, myseq 1, yourseen 0, DTE up
datagramstart
= 0xE7829994, datagramsize = 13
FR
encap = 0x00010308
00
75 51 01 00 53 02 01 00
Serial1/0(in):
Status, myseq 1, pak size 21
nRT
IE 1, length 1, type 0
nKA
IE 3, length 2, yourseq 1 , myseq 1
nPVC
IE 0x7 , length 0x6 , dlci 120, status 0x0 , bw 0
serial 1/0
Router(config-if)#encapsulation
frame-relay
Router(config-if)#no
sh
Router(config-if)#exit
Router(config)#int serial 1/0.2 multipoint
Router(config-subif)#ip address 10.1.1.1 255.255.255.0
Router(config-subif)#frame-relay map ip 10.1.1.3 130
Router(config-subif)#frame-relay map ip 10.1.1.2 120
Router(config-subif)#frame-relay interface-dlci 120
Router(config-subif)#frame-relay interface-dlci 130
Router(config-subif)#do sh run
Building
configuration...
Current
configuration : 891 bytes
!
!
interface
Serial1/0
no
ip address
encapsulation
frame-relay
!
interface
Serial1/0.2 multipoint
ip
address 10.1.1.1 255.255.255.0
frame-relay
map ip 10.1.1.3 130
frame-relay
map ip 10.1.1.2 120
frame-relay
interface-dlci 120
frame-relay
interface-dlci 130
!
同方式設定,Router-2、Router-3
Frame Relay檢修指令
1.Sh
Frame-Relay LMI:檢視Router介面與Frame Relay交換機LMI封裝協定與流量統計數據。
Router#sh frame-relay lmi
LMI
Statistics for interface Serial1/0 (Frame Relay DTE) LMI TYPE = CISCO
Invalid
Unnumbered info 0 Invalid Prot Disc 0
Invalid
dummy Call Ref 0 Invalid Msg Type 0
Invalid
Status Message 0 Invalid Lock Shift 0
Invalid
Information ID 0 Invalid Report IE Len 0
Invalid
Report Request 0 Invalid Keep IE Len 0
Num
Status Enq. Sent 169 Num Status msgs Rcvd 168
Num
Update Status Rcvd 0 Num Status Timeouts 16
LMI
Statistics for interface Serial1/0.2 (Frame Relay DTE) LMI TYPE =
CISCO
Invalid
Unnumbered info 0 Invalid Prot Disc 0
Invalid
dummy Call Ref 0 Invalid Msg Type 0
Invalid
Status Message 0 Invalid Lock Shift 0
Invalid
Information ID 0 Invalid Report IE Len 0
Invalid
Report Request 0 Invalid Keep IE Len 0
Num
Status Enq. Sent 0 Num Status msgs Rcvd 0
Num
Update Status Rcvd 0 Num Status Timeouts 16
2.Sh Frame-Relay PVC:檢視PVC與DLCI編碼,每條PVC的連線流量統計數據。
Router#sh frame-relay pvc
PVC
Statistics for interface Serial1/0 (Frame Relay DTE)
DLCI = 120, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1/0.2
input
pkts 14055 output pkts 32795 in
bytes 1096228
out
bytes 6216155 dropped pkts 0
in FECN pkts 0
in
BECN pkts 0 out FECN pkts 0
out BECN pkts 0
in
DE pkts 0 out DE pkts 0
out
bcast pkts 32795 out bcast bytes 6216155
DLCI
= 130, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE =
Serial1/0.2
input
pkts 14055 output pkts 32795 in
bytes 1096228
out
bytes 6216155 dropped pkts 0
in FECN pkts 0
in
BECN pkts 0 out FECN pkts 0
out BECN pkts 0
in
DE pkts 0 out DE pkts 0
out
bcast pkts 32795 out bcast bytes 6216155
3.Sh Frame-Relay MAP:檢視IP與DLCI編碼的對應關係。
Router#sh frame-relay map
Serial1/0.2
(up): ip 10.1.1.3 dlci 130, static, CISCO, status defined, active
Serial1/0.2
(up): ip 10.1.1.2 dlci 120, static, CISCO, status defined, active
4.Debug Frame-Relay LMI:可檢視Router介面與ISP
Frame Relay交換機的溝通訊息,協助我們觀察Router與交換機是否正確地交換LMI資訊。
Router#no debug frame-relay lmi
Frame
Relay LMI debugging is off
Displaying
all Frame Relay LMI data
Router#debug frame-relay lmi
Frame
Relay LMI debugging is on
Displaying
all Frame Relay LMI data
Serial1/0(out):
StEnq, myseq 1, yourseen 0, DTE up
datagramstart
= 0xE7829994, datagramsize = 13
FR
encap = 0x00010308
00
75 51 01 00 53 02 01 00
Serial1/0(in):
Status, myseq 1, pak size 21
nRT
IE 1, length 1, type 0
nKA
IE 3, length 2, yourseq 1 , myseq 1
nPVC
IE 0x7 , length 0x6 , dlci 120, status 0x0 , bw 0