7 Appendix: Materials and methods
7.4 Surface analysis techniques
7.4.2 Near-Ambient Pressure Photoemission (NAPP)
FRF8 requires ietf encapsulation, this is used when going from ATM to ATM and using frame-relay.
clear frame-relay inarp Used to clear bad map statements out of map cache If inverse-arp screws up the map cache this will correct it.
Ø LMI Issues
LMI Types – cisco, ansi, ccitt sh int s0
With LMI problems line protocol will be down and LMI sent will increment but LMI receieved will not be.
show frame lmi Displays the stability of you Frame connections Num Status … Sent/Recv’d should be equal
Num Status Timeouts should be 0
Use debug frame lmi to determine problem debug frame lmi Displays DTE status – should be up,
myseq should be incrementing by one yourseq should be incrementing by one Always check both sides of the connection
show frame-relay pvc PVC Status of deleted means that this pvc is no longer being reported by LMI.
Ø Other Issues show int type
show frame-relay pvc show frame-relay map sho frame-relay traffic
sho frame-relay route Displays the status of all PVC’s (dlci’S) all should be active
If not check interface configurations of inactive PVC’s, DTE device configuration
show frame-relay svc maplist
debug frame-relay events dlci problems, input problems, 25 pps or less debug serial interface hdls keepalives, displays timing problems debug ip packet
debug frame packet “encaps failed - no map entry line 7 (IP) “ Check PVS status – show frame-relay pvc
No PCS connectivity
IP: s=172.16.1.1 (local), d=172.6.1.2 (Serial0), len 100, Sending.
IP: s=172.16.1.1 (local), d=172.6.1.2 (Serial0), len 100, Sending.
IP: s=172.16.1.1 (local), d=172.6.1.2 (Serial0), len 100, Sending.”
Frame map missing at other side debug ip icmp
Is the router properly communicating to the frame-relay switch?
Does the show frame pvc display the DLCIs as active?
Are your packets leaving the router?
debug frame packet
show frame pvc (packets in / packets out)
Are your frame relay map statements correct? (Show frame map) Favorite Frame-Relay Troubleshooting Tool in a lab environment:
THE CCIE Book
debug frame packet
Ø Problem Isolation
Ø Symptom Problem Action
Local physical link Fix cabling
Configuration for PVC’s Check encap, LMI, speed Layer 2 -> 3 maps Check address configuration Remote Site OK Contact Remote Site
Link is down no keepalives sho int
Bad encryption sh frame map Dlci inactive sh frame pvc
LMI mismatch sh int serial/sf lmi Can’t Ping Remote Router bad encap
Dlci inactive
Bad access-list sh access-list
No map sfm
No broadcast in map sfm Can’t Ping end-to-end split-horizon
Access-list for protocol No gateway on workstation
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3. ISDN
The broadcast parameter allows broadcast traffic to be forwarded and broadcasts will reset the idle timer.
Just as with frame-relay map statements the dialer-map broadcast parameter is required for proper OSPF operation over a DDR link
Note that when the broadcast parameter is added the DDR link can stay up
indefinitely due to constant broadcast traffic, to remedy this situation granular dialer-lists must be configured.
A physical interface can be associated with multiple dialer pools. A logical dialer interface can be associated with only one dialer pool.
In order to configure PPP chap authentication with dialer profiles enter the PPP authentication chap statement at both the physical interface and the logical dialer interface
The dialer remote name statement is critical for the called party it must match the calling party host name or the name specified in the calling parties PPP chap host name statement
Backup for a DLCI for IP, but IPX has to flow all the time, has to be a profile
Backup a serial interface with the least number of commands.
Legacy, HDLC, and a dial string Ø Interface Types
TE2 –r– TA /TE1 –s– NT2 –t– NT1 –u– LE
BRI’s have SPIDs, PRI’s do not
Snapshot Routing The client defines the quiet period Use ppp quality for DDR based on the quality of the line.
Ø Call Setup Messages
SETUP, CALL_PROC, CONNECT, CONNECT,ASK
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Ø Teardown Messages DISCONNECT, RELEASE,
Ø ISDN and OSPF
Add the broadcast to dialer maps
Ø Routing over DDR
Floating statics with dynamic routing protocol OSFP demmand circuit distr-list
snapshot routing (RIP,IGRP,IPX RIP)
BGP -- long keepalive timer + default idle timer no peer neighbor-route
DLSw -- turn off keepalive or use dynamic with inactivity Bridge(over tunnel) -- turn off spanning tree
EIGRP - Filter the hellos (224.0.0.10) access-list 101 deny eigrp any any
access-list 101 deny ip any 224.0.0.10 0.0.0.0
Supress-state-change-updates – prevents routing traffic on line when line was initated by interesting traffic. Need dialer parameter as well since this is what allows a call for routing traffic.
Ø Basic Configuration Needs
Info you need to configure is:
BRI DN, SPID, Signaling protocol PRI Timeslot 24 is for D Channel
Controller, framing, linecode, pri-group
Basic ISDN (3 statements)
Add Authentication (3 statements)
Add Dialer-list complexity (3 interface / 1 Global statements) Four step Configuration
Define Interesting Traffic dialer list
Map Destination dialer map
Define interface dialer group
Options dialer idle-timeout
dialer fast-idle
dialer load- threshold
Ø Basic Configuration
This is the basic configuration for a ISDN connection.
Notice three ISDN, dialer, and ppp statements are required.
R1
username r2 password 0 sanfran isdn switch-type basic-ni interface BRI0
ip address 199.10.10.1 255.255.255.0 isdn switch-type basic-ni
isdn spid1 0835866101 8358661 isdn spid2 0835866301 8358663
dialer idle-timeout 90 ! Interesting traffic timeout dialer map ip 199.10.10.2 name r2 broadcast 8358662 ! Map command or
dial string 8358662
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! Need a static map with just a dail string to send traffic
! Dial strings and maps are to dial out only
! These are not needed if the router is to receive calls only dialer-group 1 ! Assign dialer list 1 to int encapsulation ppp
ppp authentication chap
ppp multilink ! Negotiate MLPPP
dialer-list 1 protocol ip permit ! Define interesting traffic R2
username r1 password 0 sanfran isdn switch-type basic-ni interface BRI0
ip address 199.10.10.2 255.255.255.0 isdn switch-type basic-ni
isdn spid1 0835866201 8358662 isdn spid2 0835866401 8358664 dialer idle-timeout 90
dialer map ip 199.10.10.1 name r1 broadcast 8358661 dialer-group 1
encapsulation ppp
ppp authentication chap ppp multilink
Ø General L2 Connectivity R1
isdn switch-type basic-ni int bri 0
isdn switch-type basic-ni isdn spid1 0835866201 8358662 isdn spid2 0835866401 8358664 R5
isdn switch-type basic-ni int bri 0
isdn switch-type basic-ni isdn spid1 0835866101 8358661 isdn spid2 0835866301 8358663
Ø Configuration
(3) Basic ISDN commands (switch-type / spids) (3) Add Authentication
(3+1) Add Dialer-list complexity (3 interface and 1 global statements) Four step Configuration
Define Interesting Traffic dialer list Define interface dialer group
Map Destination dialer map
Options idle-timeout, fast-idle, load- threshold
Ø Example:
R1
username r2 password 0 sanfran isdn switch-type basic-ni interface BRI0
ip address 199.10.10.1 255.255.255.0 isdn switch-type basic-ni
isdn spid1 0835866101 8358661 isdn spid2 0835866301 8358663
THE CCIE Book
dialer idle-timeout 90 ! Interesting traffic timeout dialer map ip 199.10.10.2 name r2 broadcast 8358662 ! ap command or
dial string 8358662
! Need a static map with just a dail string to send trffic
! Dial strings and maps are to dial out only
! These are not needed if the router is to receive calls only dialer-group 1 ! Assign dialer list 1 to int encapsulation ppp
ppp authentication chap
ppp multilink ! Negotiate MLPPP
dialer-list 1 protocol ip permit ! Define interesting traffic
Ø Call Messages
SETUP, CALL_PROC, CONNECT, CONNECT,ACK DISCONNECT, RELEASE,
Ø BRI Configuration
Configure the isdn switch, for all configurations int bri 0
isdn switch-type basic-ni1 no shutdown
Verify that the router is communicating with the switch show isdn status
debug isdn q921
Layer 1 should be ACTIVE
Layer 2 state = MULTI_FRAME_ESTABLISHED
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3.1. S ETUP
Some of the mandatory decisions that must be made are:
A.) What type of encapsulation am I going to use on my interface?
HDLC, PPP
B.) What kind of traffic will be able to generate outbound calls?
Dialer-lists
C.) What kind of traffic do I want to prevent from making outbound calls?
ACL
D.) Will I always be dialing the same location or multiple remote locations?
Dialer map, dialer strings (up to three) great for hub – spoke connectivity or for a backup router.
Need dialer maps when calling two different locations (on hub) Dialer strings can be used on spokes.
Dialer maps can set the speed, host name, of the call and determine if broadcast traffic should be sent, broadcast traffic is optional.
“All ip addresses that are put it the dialer maps must be in the routing table, if not you must put them in the routing table with statics.”
E.) If I'm dialing multiple remote locations can I use the same parameters for all of them such as authentication type, IP subnets, layer3 protocols allowed during the call, etc?
chap never sends passwords across the link pap send password in clear text
Changing hostnames:
CHAP - ppp chap hostname x
PAP - ppp pap sent-username x password y"
F.) After all the data transmission is done how long do I want to wait before the call is disconnected?
Never rely on the remote routers to disconnect your calls in a timely manner. If you're worried about ISDN charges make sure you take control by configuring your router with the appropriate disconnect timer.
G.) Am I going to allow dynamic routing protocols to use the ISDN link or just static routes?
Dynamic routing without keepalives:
H.) If I use both B-channels on the call (either inbound or outbound) do I want to use the PPP Multilink feature to fragment large packets into smaller ones?
When do you want the second link to come up?
dialer load-threshold x outbound | inbound | either” where “x” is a value between 1 and 255. The number range of 1 to 255 correlates to the current bandwidth usage or load of the call with 255 being equated to an existing load of 100%. So as an example, if I wanted to configure my ISDN DDR interface such that when the first B-channel reached a load if 50% it would automatically bring up the next available B-channel I would
configure the command, “dialer load-threshold 128” because 128 is
approximately 50% of the maximum value of 255. If I didn't want additional B- channels to be added unless the first B-channel was 100% utilized I would modify the command to “dialer load-threshold 255”.
ppp multilink – breaks packets into smaller packets for optimized delivery for two links.
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I.) Do I want to implement ppp callback?
J.) IP Addressing scheme.
1.) Do you want to place a static IP Address on your ISDN interface? No 2.) Do you want to have your ISDN interface unnumbered to some other
physical or logical interface on the router? ip unnumbered lo0, ip unnumbered dialer1
3.) Do you want to obtain your IP address for the ISDN interface dynamically during each call via IPCP?
Obtain an IP address from an IPCP pool on a remote router. This is most often used in hub and spoke situations where a pool of address resides on the Hub router and is used to dynamically assign an IP address via IPCP to individual PCs that dial in with an ISDN Terminal Adapter. This can also work when you have Spoke Routers that dial in via PPP.
Hub router:
Single ip address: peer default ip address x.x.x.x
Multiple IP Addresses: ip local pool CCIELAB x.x.x.x y.y.y.y peer default ip address pool CCIELAB
Spoke Routers: ip address negotiated