CCIE R&S Advanced Technologies Class v4.5

Transcript

1	Introduction	0h 43m
2	Using the Cisco Documentation	0h 52m
3	Ethernet Overview, Layer 2 Switchports, Trunking, ISL, 802.1q, DTP	0h 47m
4	VTP, VTP Authentication, VTP Pruning	1h 02m
5	VTP Prune Eligible List, VTP Transparent, VTP Troubleshooting, Trunk Allowed List, Extended VLANs	0h 48m
6	VLAN and VTP Review	0h 19m
7	SVIs, Native Routed Interfaces, Router-on-a-Stick	0h 46m
8	Layer 2 EtherChannel, EtherChannel Load Balancing, Layer 3 EtherChannel	0h 57m
9	802.1q Tunneling, Layer 2 Protocol Tunneling, EtherChannel over 802.1q Tunneling	1h 03m
10	STP Root Bridge Election, STP Root Port Election, STP Designated Port Election, STP Priority, STP Cost, STP Port-Priority	1h 06m
11	STP Review	0h 12m
12	STP Timers, STP PortFast	0h 34m
13	STP UplinkFast	0h 11m
14	STP BackboneFast	0h 12m
15	STP BPDU Filter	0h 13m
16	STP BPDU Guard	0h 11m
17	STP Root Guard	0h 11m
18	STP Loop Guard, Unidirectional Link Detection (UDLD)	0h 11m
19	Multiple Spanning-Tree Protocol (MST)	0h 40m
20	Rapid Spanning-Tree Protocol (RSTP), Rapid-PVST	0h 18m
21	MST with Multiple Regions	0h 33m
22	Flex Links	0h 16m
23	Frame Relay	0h 39m
24	Frame Relay Configuration Part 1	0h 34m
25	Frame Relay Configuration Part 2	0h 41m
26	Frame Relay Switching	0h 27m
27	Back-to-Back Frame Relay	0h 08m
28	Frame-Relay End-to-End Keepalives	0h 18m
29	PPP, PPP PAP Authentication, PPP CHAP Authentication	0h 59m
30	PPPoFR, PPPoE	0h 40m
31	Transparent Bridging, IRB	0h 32m
32	Fallback Bridging	0h 14m
33	IP Routing Overview, Switching Paths, Static Routing	0h 42m
34	Static Routing Examples	0h 25m
35	IP Default-Gateway, IP Default-Network	0h 14m
36	On-Demand Routing (ODR)	0h 07m
37	Floating Static Routes	0h 10m
38	Backup Interface	0h 29m
39	Enhanced Object Tracking, IP SLA, Reliable Static Routing	0h 21m
40	Policy Routing	0h 43m
41	GRE Tunneling, GRE Recursive Routing Errors	0h 27m
42	Reliable Backup Interface with GRE	0h 25m
43	RIP Overview, RIP Versions, RIP Auto-Summary	0h 48m
44	RIP Split-Horizon, RIP Timers	0h 22m
45	RIP Broadcast Updates, IP Directed Broadcast, IP Broadcast-Address, Smurf Attacks, Fraggle Attacks	0h 16m
46	RIP Unicast Updates	0h 03m
47	RIP Offset-List	0h 18m
48	RIP Authentication	0h 11m
49	RIP Summarization	0h 10m
50	Prefix-Lists, RIP Distribute-List Filtering, RIP Administrative Distance Filtering	0h 48m
51	RIP Default Routing, RIP Conditional Default Routing	0h 18m
52	RIP Triggered, RIP Validate Update Source,	0h 12m
53	EIGRP Overview	0h 29m
54	EIGRP Auto-Summary	0h 07m
55	EIGRP Split-Horizon	0h 11m
56	EIGRP Update Types, EIGRP Neighbor, EIGRP Passive-Interface	0h 24m
57	EIGRP Hello-Interval, EIGRP Hold-Time	0h 05m
58	EIGRP Authentication	0h 11m
59	EIGRP Time Based Authentication	0h 25m
60	EIGRP Path Selection, EIGRP Metric Weights, EIGRP Traffic Engineering	0h 47m
61	EIGRP Unequal Cost Load Balancing, EIGRP Variance	0h 19m
62	EIGRP QUERY, EIGRP Summarization, EIGRP Leak-Map	0h 28m
63	EIGRP Stub Router Advertisement	0h 22m
64	EIGRP Default Routing	0h 13m
65	EIGRP Route Filtering	0h 11m
66	EIGRP Router-ID	0h 07m
67	Miscellaneous EIGRP Features	0h 02m
68	OSPF Overview	0h 27m
69	Establishing OSPF Adjacencies, Understanding the OSPF Database	0h 43m
70	OSPF Network Type Broadcast, OSPF DR/BDR Election, OSPF over NBMA, OSPF Network Type Non-Broadcast and Point-to-Multipoint	0h 56m
71	OSPF Network Type Point-to-Point, OSPF Network Type Mismatch	0h 13m
72	OSPF Network Type Point-to-Multipoint Non-Broadcast, OSPF Per Neighbor Cost	0h 17m
73	OSPF Network Type Loopback	0h 02m
74	OSPF Path Selection	0h 27m
75	OSPF Convergence Timers	0h 09m
76	OSPF Authentication	0h 12m
77	OSPF Summarization	0h 32m
78	OSPF Stub Areas, OSPF Totally Stubby Areas, OSPF NSSAs, OSPF Totally NSSAs	0h 40m
79	Controlling OSPF NSSA Redistribution	0h 02m
80	OSPF Type 7 to 5 Translator Election, OSPF LSA Type 3 Filter, OSPF Forwarding Address Suppression	0h 24m
81	Route Redistribution Overview	0h 36m
82	Route Redistribution Configuration & Verification, Connected Redistribution	0h 22m
83	OSPF External Path Selection, TCL PING Scripting	0h 33m
84	Routing Loops Overview, EIGRP Route Loop Prevention	0h 55m
85	Metric Based Routing Loops, Route Tagging	0h 46m
86	Administrative Distance Based Routing Loops, Debug IP Routing, IP Route Profile	0h 58m
87	BGP Overview, BGP Peering Types	0h 51m
88	Establishing BGP Peerings, EBGP Multihop, BGP Neighbor Disable Connected Check, BGP TTL Security	0h 49m
89	BGP 4-Byte ASNs	0h 20m
90	BGP Local AS, BGP Peer Groups	0h 30m
91	BGP Next-Hop Self, BGP Next-Hop Processing	0h 30m
92	BGP Route Reflectors	0h 37m
93	Large Scale BGP Route Reflectors with Clusters	0h 34m
94	BGP Confederation	0h 37m
95	BGP NLRI Advertisements, BGP Network Statement, BGP Redistribution	0h 43m
96	BGP Aggregation, BGP Aggregation & Summary-Only, BGP Aggregation & Unsuppress-Map	0h 46m
97	BGP Origin, BGP Aggregation & AS-Set, BGP Aggregation & Advertise-Map	0h 22m
98	BGP Conditional Route Injection	0h 21m
99	BGP Bestpath Selection, BGP Multipath, BGP Weight	0h 53m
100	BGP Local Preference, BGP Local Preference and Communities, BGP AS-Path Prepending,	0h 30m
101	BGP MED, BGP MED Missing As Worst, BGP Deterministic MED	0h 17m
102	BGP Communites, BGP Regular Expressions	0h 43m
103	BGP Filtering, BGP Convergence Timers, BGP Default Routing, Miscellaneous BGP Features	0h 24m
104	MPLS Overview, MPLS Label Distribution Protocol (LDP)	1h 05m
105	MPLS Tunnels, MPLS Penultimate Hop Popping (PHP)	0h 40m
106	MPLS Layer 3 VPNs Overview, VRF Lite	0h 36m
107	MPLS Layer 3 VPNs and VPNv4 BGP	1h 08m
108	MPLS Layer 3 VPN Verification & Troubleshooting	0h 49m
109	MPLS Layer 3 VPN OSPF PE-CE Routing Overview	0h 06m
110	MPLS Layer 3 VPN OSPF PE-CE Routing Path Selection & Sham-Links	2h 01m
111	MPLS Layer 3 VPN OSPF PE-CE Routing Loop Prevention & Down-Bit, OSPF Capability VRF-Lite	0h 40m
112	IPv6 Overview, IPv6 ICMPv6 ND, IPv6 over NBMA	0h 44m
113	IPv6 Routing Overview, IPv6 Static Routing	0h 28m
114	IPv6 RIPng	0h 20m
115	IPv6 EIGRPv6	0h 09m
116	IPv6 OSPFv3	0h 31m
117	MP-BGP for IPv6	0h 26m
118	IPv6 Tunneling	1h 13m
119	Multicast Overview, IGMP	0h 34m
120	PIM Overview	0h 18m
121	PIM Dense Mode	1h 03m
122	PIM Sparse Mode	0h 30m
123	PIM Sparse Mode Configuration	0h 36m
124	PIM Sparse Mode RPF & RP Troubleshooting	0h 27m
125	Auto-RP, Multicast over GRE Tunnels	0h 53m
126	Bootstrap Router (BSR), Bidirectional PIM, Source Specific Multicast (SSM)	0h 40m
127	MSDP, Anycast RP	0h 27m
128	IPv6 Multicast Routing	0h 24m
129	QoS Overview, IntServ QoS, DiffServ QoS, IP Precedence, DSCP, MQC, HQF	0h 41m
130	MQC Classification	0h 44m
131	FIFO, FQ, WFQ, CBWFQ, HQF	0h 50m
132	LLQ	0h 23m
133	WRED	0h 31m
134	Traffic Shaping, Traffic Policing	0h 40m
135	Frame Relay Traffic Shaping (FRTS)	0h 33m
136	RSVP	0h 07m
137	Catalyst 3560 QoS	1h 00m
138	IOS Security Overview, Access Lists (ACLs)	0h 58m
139	Time Based ACLs, Dynamic ACLs	0h 33m
140	Reflexive ACLs	0h 21m
141	TCP Intercept, Content Based Access Control (CBAC)	0h 34m
142	Zone Based Policy Firewall (ZBPF)	1h 09m
143	AAA, Local Authentication, Local Authorization, Role Based CLI Access	0h 43m
144	Port Security, Static CAM Entries, Storm Control, 802.1X Authentication, PACLs, RACLs, VLAN Access Maps (VACLs)	0h 48m
145	DHCP Snooping, Dynamic ARP Inspection (DAI), IP Source Guard	0h 12m
146	Protected Ports, Private VLANs	0h 25m
147	IP Services Overview, HSRP	1h 10m
148	VRRP, GLBP	0h 28m
149	NAT	0h 42m
150	DHCP, DNS	0h 30m
151	NetFlow	0h 09m
152	WCCP, Miscellaneous IP Services	0h 06m
153	System Management Overview, NTP, NTP Authentication	0h 24m
154	SNMP, RMON	0h 38m
155	Syslog, Telnet, SSH, Banners	0h 21m
156	EEM Scripting, Miscellaneous System Management	0h 26m
Total Duration		81h 02m

Slides - Diagrams

Slides - Introduction

Slides - Ethernet Switching

Slides - Advanced Ethernet Switching

Slides - Frame Relay

Slides - PPP

Slides - Transport Bridging

Slides - Redistribution

Slides - IOS Security

Slides - Layer 2 Security

Slides - IP Services

Slides - System Management

0:00:14	Another variation of this type of...
0:00:18	routing between two different interfaces where
0:00:24	would be to use the
0:00:27	Now, Backup Interface originally
0:00:33	where we would have one primary link that's maybe
0:00:39	and then, some sort of either
0:00:44	where we would only want to use the dial
0:00:50	or it was exceeding
0:00:55	The reason behind this...
0:00:57	is that these analogue or digital
0:01:02	were typically pay-per-use.
0:01:05	So, you wouldn't wanna be using it as your
0:01:11	but if it's your only option to get out of the network,
0:01:17	This would then imply, if we were to
0:01:22	for this feature, the Backup Interface,
0:01:24	if we go to the Configuration Guides,
0:01:27	this is actually gonna be
0:01:33	If we go to the Dial
0:01:36	Dial Back-up Configuration,
0:01:40	Configuring Dial-Backup for Serial Lines,
0:01:47	So, Dial-Backup with the Dialer Profile, this
0:01:51	and we're the PPPoE client.
0:01:54	The only difference is that the
0:01:57	would be going on
0:02:00	as opposed to the physical link.
0:02:07	So, there are some additional minor
0:02:11	besides just using the
0:02:13	You get to find the
0:02:16	So, if we say that our
0:02:23	a particular threshold,
0:02:27	So, Backup Load...
0:02:29	Enable Threshold and
0:02:33	it says that, "This is over a 5-minute
0:02:38	This is what is controlled...
0:02:42	at the link level...
0:02:45	by the...
0:02:47	if we go to the...
0:02:48	the main serial interface,
0:02:50	the Load Interval command.
0:02:54	So, if we were to say,
0:02:57	it means that we're looking at
0:03:01	Where by default, it is
0:03:04	If we were then to say,
0:03:08	this is the primary link,
0:03:11	I'll say here that serial...
0:03:13	0/1/0 is my Backup Interface.
0:03:19	So, from a routing point of view,
0:03:23	this means that I'm gonna send
0:03:29	but if that link is down,
0:03:37	Now, with this configuration, since only one of
0:03:43	it's independent of either the routing metric
0:03:49	As long as router 5 has some routing
0:03:53	and then some back up routing information pointing out the backup link.
0:03:57	it doesn't matter what the
0:04:01	So, my previous floating static
0:04:06	except that it's kind of a backwards logic,
0:04:11	is actually the one with the...
0:04:15	higher administrative distance,
0:04:18	so, this would be our primary route.
0:04:21	Simply because the first route...
0:04:24	cannot perform route recursion.
0:04:28	If we look at the Show
0:04:31	we see that serial 0/1/0
0:04:37	which means that its
0:04:45	So again, the key point here...
0:04:47	is that a route can only be
0:04:49	if the interface that it recurses to
0:04:51	has its line protocol in the up state.
0:04:58	If the line protocol is down,
0:05:02	then, no routes can
0:05:06	If we look at the result
0:05:09	and Show IP Route...
0:05:12	Static,
0:05:15	we see that the route installed is the
0:05:20	So, if I were to do a traceroute to...
0:05:24	router 4's loopback,
0:05:27	that's gonna go over
0:05:30	Now, if the frame relay link's
0:05:34	we would then see the
0:05:41	until the primary link comes back.
0:05:48	Now, one way we could
0:05:51	would be to change the
0:05:55	because again, it's the LMI that determines whether the
0:06:01	If I were to shut the interface
0:06:05	so, I'll just say Shutdown,
0:06:07	this is not going to trigger
0:06:11	If I Show IP Interface Brief,
0:06:15	the Backup Interface says that...
0:06:18	"I'm in the standby mode,
0:06:23	so I'm not gonna automatically use this."
0:06:29	This feature was there as a prevention
0:06:32	in dial backup scenarios
0:06:34	where you manually shutdown
0:06:37	and then, it would cause your analogue,
0:06:42	and then...
0:06:43	at the end of the building cycle, you get
0:06:51	In our case, it's not
0:06:54	we're assuming that the
0:06:57	It doesn't really matter
0:06:59	But you could run into this situation
0:07:04	and they're very low speed,
0:07:07	You could do some sort of dial-backup
0:07:15	but the key point of this is that if we're trying
0:07:20	shutting down the primary
0:07:24	We would have to figure out some way
0:07:28	where the link status is either...
0:07:31	up with the protocol down,
0:07:35	not administratively down.
0:07:44	So, if our primary link is up,
0:07:48	when we Show IP Interface Brief,
0:07:52	this means that the Backup
0:07:56	If I were to go to the
0:08:02	and say, "The frame relay
0:08:07	So, it's something that's not the Cisco type.
0:08:12	We should see...
0:08:15	that when we look at the
0:08:20	once we receive a number
0:08:27	the line protocol of the main
0:08:34	We could also here look
0:08:40	Debug Backup.
0:08:42	This will show us if were trying to do any type of
0:08:49	It will tell us what's the state of the
0:08:53	So, in this case, it says, "Now,
0:08:57	So, the secondary interface
0:09:01	Or, excuse me, secondary
0:09:04	So now, it says "The event happen where
0:09:09	Serial 0/1/0 is now up",
0:09:12	which means that routes pointing out there...
0:09:16	can now be installed in the routing table.
0:09:19	So, if we look at the Show IP Route Static,
0:09:26	we have the route of the point-to-point link,
0:09:30	and if we trace the router 4's loopback,
0:09:34	we could see, we're routing over that secondary
0:09:45	So, pretty straightforward configuration here, the only
0:09:53	we have the Backup Interface command,
0:09:58	Then, we have some
0:10:01	whether it's static or dynamic
0:10:04	that is eventually gonna get us to route
0:10:08	and then, the secondary
0:10:12	So, Backup Interface doesn't
0:10:15	We still need some other protocol to figure
0:10:20	In this case, we're doing it with...
0:10:24	just two static routes.
0:10:27	Now, if I were to set the administrative
0:10:33	it's still not going to affect anything.
0:10:34	Because we're choosing
0:10:38	simply based on which interface is active.
0:10:41	Is the frame relay up-up?
0:10:44	Or is the frame relay up-down or down-down,
0:10:53	So now, we're gonna have some problems
0:10:58	We'll see issue with this implementation.
0:11:01	Anytime where the line protocol status
0:11:05	is not a good indication of actual
0:11:11	We'll see, this is the case where
0:11:15	and any type of Metro Ethernet.
0:11:18	Okay, or basically, any Ethernet that were going to
0:11:25	The case for Ethernet
0:11:28	is that if we have router 1,
0:11:31	and router 2
0:11:33	that are physically connected over Ethernet.
0:11:39	So, we have a gigabit Ethernet link that
0:11:44	So, there's across sort of
0:11:48	If we had a second design where router 1
0:11:54	and router 2 is likewise,
0:11:58	G 0/0 goes to G 0/0,
0:12:02	G 0/1 goes to G 0/1.
0:12:06	The problem in this type of design now...
0:12:09	is that if router 2...
0:12:11	has an interface failure,
0:12:14	it is not gonna update the line
0:12:21	For the first topology at the top,
0:12:23	if router 2's interface goes down,
0:12:26	it implies then that router 1's
0:12:30	Because there's a physical back to
0:12:33	But anytime there is someone else to
0:12:38	which in this case,
0:12:42	then the end to end reachability...
0:12:45	is not gonna be indicated
0:12:51	In the case of frame relay,
0:12:54	this would be if one side of the link is up-up,
0:12:58	but the circuit status is down,
0:13:02	the router will have no way to detect that.
0:13:07	So here, we have router 4,
0:13:09	and router 5
0:13:11	connected over frame relay.
0:13:15	Router 4 is using a point-to-point sub-interface.
0:13:19	s0/0/0.1.
0:13:24	Point to point.
0:13:26	Router 5 is using the
0:13:32	Then, we have the circuit between them,
0:13:35	On router 5, this is 504.
0:13:39	We saw them on router 5,
0:13:44	and said that the frame relay LMI type...
0:13:49	was something that switch did
0:13:53	You could also say, Q933A.
0:13:58	This then means that router 5
0:14:02	which would then send the
0:14:10	So, the physical link is up, but there's
0:14:15	However, if router 4's
0:14:25	so, router 4 sees its interface as...
0:14:29	down-down,
0:14:31	or up-down.
0:14:33	Okay, or even admin down, if we
0:14:38	The main interface status on
0:14:46	If we look at the Show
0:14:48	router 5 will know that the
0:14:53	but that is not going to update the line
0:15:00	So, this would mean a
0:15:03	Let's say that we want the same type of design
0:15:08	But I want to take into
0:15:12	where router 5 looses
0:15:15	or router 4 looses connectivity to the switch.
0:15:19	Where in either case, I'm able to
0:15:25	If we were to put the Backup
0:15:30	that would only take into account the case
0:15:37	It would not take into account any case where
0:15:43	or if there was a failure on router 4's end.
0:15:48	However, if I were to configure the
0:15:52	and put it on the sub-interface,
0:15:57	the sub-interface's line protocol status is directly
0:16:06	So, this means that if the PVC status...
0:16:09	is active,
0:16:12	the link...
0:16:14	is up-up.
0:16:17	But if the PVC status is inactive,
0:16:22	or deleted,
0:16:27	then, the link is gonna be down.
0:16:29	The line protocol is gonna be down.
0:16:33	If the line protocol is be down,
0:16:35	it means that the subnet
0:16:38	cannot get installed into the routing table,
0:16:41	which then in turn means that any routes that recurse
0:16:50	So, there is a difference in this design where
0:16:55	If we put it on router 5,
0:16:56	it's only gonna work in
0:16:59	On router 4, it should theoretically
0:17:03	assuming that the LMI status actually is a good
0:17:11	Now, we can see this in the command line,
0:17:16	and...
0:17:18	Shut the frame relay interface down,
0:17:25	so, we now know that router...
0:17:28	5 and 4,
0:17:30	they're not gonna be able to reach each other over
0:17:35	But if we look at router 5 and
0:17:45	or the Show IP Interface Brief,
0:17:50	notice that serial 0/0/0...
0:17:54	Actually, it is down here...
0:17:59	Let's see... This is probably...
0:18:07	Because I changed the LMI.
0:18:09	So, on the link, let's say,
0:18:15	We'll let the router automatically detect it.
0:18:19	And also, I'll remove those other mappings.
0:18:25	these loopback addresses.
0:18:45	So, we see now, router 5's link status is up.
0:18:47	And the line protocol...
0:18:49	Line protocol in the frame relay is up,
0:18:53	which then means that the Backup
0:18:58	If we Show IP Interface Brief,
0:19:02	the frame relay interface is up-up,
0:19:06	which means, the Backup
0:19:12	The problem now is that if we
0:19:17	the final destination,
0:19:21	we're not able to reach it,
0:19:26	If we look at the Show Frame Relay PVC,
0:19:35	and we're looking at circuit number 504,
0:19:44	we could see, 504 is inactive.
0:19:49	It's inactive because the switch is saying,
0:19:55	But the problem is, since router 5 is still
0:20:01	it cannot set the line
0:20:04	Because in reality, there's other
0:20:07	We would not want the case where
0:20:13	then it would mean we can't
0:20:20	Because these other circuits are up.
0:20:30	So again, if we look at the
0:20:34	Static.
0:20:37	Now, our Backup Interface scenario is failing.
0:20:43	So now, let's try it on the other end.
0:20:46	We'll say, No Backup Interface Serial 0/1/0.
0:20:51	And on router 4,
0:20:55	I'll bring the frame relay interface up.
0:21:01	Then, on our frame relay sub-interface.
0:21:04	So, if we Show IP Interface Brief,
0:21:09	this sub-interface is serial...
0:21:14	0/0/0.1.
0:21:23	So, it's a point-to-point sub-interface, the only thing we have
0:21:25	applied is just the IP address and the circuit number.
0:21:28	We don't need to worry
0:21:30	We don't need to worry about inverse ARP,
0:21:35	On the sun-interface,
0:21:38	we'll say that our Backup Interface is the...
0:21:44	physical point-to-point serial that goes to router 5.
0:21:47	Which is as 0/1/0.
0:21:50	Now, we can see, that's in standby mode.
0:22:00	So, the primary link...
0:22:03	is up-up. This is the sub-interface.
0:22:10	The Backup Interface is in standby mode.
0:22:16	So now, let's look at the case where...
0:22:19	router 5 looses connectivity.
0:22:24	Or if we had access to the switches, we could
0:22:28	or shut one of the
0:22:31	In this case, I'm just gonna shut
0:22:38	So, on router 5, we'll say that the
0:22:47	Now, this of course is gonna cause
0:22:51	because the...
0:22:54	primary link is no longer there.
0:22:56	It means that I cannot...
0:22:59	I cannot install route for it.
0:23:02	But notice now that the
0:23:09	We see now, the secondary link in installed.
0:23:12	If we try to send traffic
0:23:16	we could see it goes through.
0:23:18	If we look at router 4,
0:23:21	it says that, "Serial 0/1/0 came up."
0:23:26	And it really doesn't tell us why, but if
0:23:32	we can see now that
0:23:35	The frame relay sub-interface.
0:23:40	The reason why is that if we look at the...
0:23:44	Show Frame Relay PVC,
0:23:47	and look at the DLCIs.
0:23:50	All of the circuits that are
0:23:55	which in this case is just a single circuit,
0:24:01	The status is not active.
0:24:04	If it is either inactive or deleted,
0:24:08	it means that the
0:24:14	Since we have the Backup Interface
0:24:19	this then means that no
0:24:23	router 4 should be able to detect this.
0:24:26	And then, fail over to the backup link.
0:24:38	So, there's really no
0:24:41	It's more of just a design issue
0:24:43	that when we apply the Backup
0:24:46	it should be on some device that is able
0:24:53	Router 5 cannot properly do that,
0:24:55	because it has a multipoint interface
0:25:02	Now, the same would be true if
0:25:05	For a multipoint sub-interface,
0:25:08	if all circuits assigned are not in the active
0:25:16	At least one of them is...
0:25:19	in the active state, then,
0:25:24	So, if we had a case where...
0:25:27	router 5...
0:25:30	had...
0:25:37	the connection to all of the spokes,
0:25:40	that goes to router 1, router 2,
0:25:42	router 3,
0:25:44	and router 4.
0:25:47	If we were to use a sub-interface here,
0:25:52	now, we know there's multiple DLCIs so that means
0:25:59	If router 5 runs into the case that every
0:26:06	then, the line protocol of the multipoint
0:26:13	So, as I mentioned in
0:26:16	design-wise, if you were to choose how
0:26:20	your first choice would be to use
0:26:25	The reason why is that it simplifies
0:26:30	and also, it should be in theory.
0:26:33	A good indication of the
0:26:38	Your next choice would then be
0:26:42	because likewise, the multipoint
0:26:46	is based on the underlying
0:26:52	Unfortunately, the case that
0:26:55	is when LMI is not end to end between the routers.
0:27:01	A typical case for this in today's networks...
0:27:05	is if router 4 has frame relay on the edge.
0:27:12	So, router 4 is the customer edge,
0:27:15	and it's connecting to some provider edge router.
0:27:18	Then, we're going to the cloud.
0:27:22	Coming out on another provider edge router,
0:27:26	and going to router 5.
0:27:30	In most real network designs today,
0:27:34	the last hop link would be running frame relay.
0:27:39	But the core of the network would not.
0:27:41	This would actually be MPLS.
0:27:45	So, what happens is that these two PE routers,
0:27:47	PE1 and PE2,
0:27:49	they're forming a Layer 2 VPN...
0:27:56	using the...
0:27:57	using the Any Transport over
0:28:01	which basically is taking the frame relay
0:28:03	frames as they come in.
0:28:06	And then, encapsulating them inside IP.
0:28:11	When we do this, you loose the
0:28:17	So, if theoretically, there was a failure
0:28:20	router 5 and router 4, they're not
0:28:26	Where this is also applicable...
0:28:28	like I mentioned before would
0:28:32	So, if an Ethernet link is
0:28:36	the link status on one side is not gonna
0:28:42	So, this means that when you are
0:28:46	If you're using Ethernet as just
0:28:50	you should take the first design
0:28:56	In the second design where you're going
0:29:01	it means the line protocol of one router...
0:29:03	does not reflect the line
0:29:10	Now, we'll see, there are
0:29:13	There is a media independent Layer 2 protocol
0:29:18	that was specifically invented to fix this problem,
0:29:22	which is called, "Bi-directional
0:29:27	So, BFD is the same logic as frame
0:29:31	or the ATM Operation and
0:29:37	But with BFD,
0:29:38	you could run it o Ethernet, you could
0:29:42	you could run it over frame relay.
0:29:43	It's independent of the underlying media.
0:29:50	So again, with the problem we saw
0:29:53	is that if the line protocol status in one side...
0:29:56	is not a good representation of the
0:30:00	some of these failure scenarios will

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CCIE R&S Advanced Technologies Class v4.5
Title:	CCIE R&S Advanced Technologies Class v4.5
Duration:	81h 02m
The CCIE Routing & Switching Advanced Technologies Class is the first step in understanding CCIE level technologies and is a companion to the Advanced Technologies Lab Workbook. Each technology you need to know for the CCIE Routing & Switching lab will be described in detail using an instructor led hands on demonstration. The class consists of over 80 hours of in depth explanations and examples.
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Backup Interface

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