CCIE Routing & Switching Advanced Technologies Class

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 46m
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 34m
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 59m

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

0:00:13	The next distance-like behavior that we have for EIGRP
0:00:17	is that it does still use Split Horizon.
0:00:20	Now, when EIGRP Split Horizon is not really used as a loop prevention mechanism
0:00:27	as more so, it's used just to make the updating process a little bit more efficient.
0:00:33	Because normally, there's not a case where you woud advertise a route to me,
0:00:37	and then I should advertise it right back to you.
0:00:40	Really, the only valid design case for that
0:00:43	is if we're running some sort of partially meshed non-broadcast topology.
0:00:48	We'll see, this would be true of designs today,
0:00:52	where it's very common to run EIGRP,
0:00:56	which is for a Dynamic Multipoint VPN, or DM VPN.
0:01:04	Where DM VPN is basically a multipoint GRE tunnel
0:01:09	that we can use between a hub and the different spokes
0:01:14	to essentially form an automatic full mesh of IP Sec tunnels.
0:01:22	And in these type of designs, typically, EIGRP
0:01:25	is the IGP that is used to route them.
0:01:29	So, in this practical design, on the hub,
0:01:33	when it receives an update in one of the tunnels from the spokes,
0:01:37	it would need to disable Split Horizon so that it can go back out the same interface down to the other spokes.
0:01:45	We'll see the same logical case in our topology
0:01:50	with the frame-relay interface that router 5 is using.
0:01:56	So, as opposed to the RIP process
0:01:59	where RIP automatically disables Split Horizon on the main interface in frame-relay,
0:02:05	EIGRP is gonns use Split Horizon on every single interface.
0:02:10	So, this would then mean, when router 2 sends an update to 5,
0:02:14	5 is not gonna be able to send this back to 3, to 1, or to router 4.
0:02:20	So, on router 5's interface,
0:02:23	wherever the IP address is assigned either under the main interface in frame-relay,
0:02:27	or potentially, a multipoint sub-interface,
0:02:30	we would then wanna go and disable the Split Horizon process.
0:02:36	Now, we will see what will happen is that when router 2 now sends an update to router 5,
0:02:45	5 is gonna send it right back to router 2,
0:02:49	but based on the logic of the feasibility condition,
0:02:53	router 2 will know that it is never valid to use router 5 to reach those destinations.
0:03:00	So, once Split Horizon is off, then, we look at the Show IP EIGRP Topology All Links,
0:03:05	we will see that there's a bunch of duplicate information that is advertised between the routers.
0:03:11	So, this is the real reason that Split Horizon is on.
0:03:14	Not for loop prevention, but just to make sure that I'm not sending an update to you,
0:03:19	and then, you're sending it right back to me.
0:03:21	Because I'm still gonna have to process that update,
0:03:24	and use it as part of my calculation before I can throw it away.
0:03:30	Now, we could see that this is the case on router 2.
0:03:34	If we were again similar to our RIP configuration,
0:03:37	if we were to disable the link that router 2 connects to router 3 with,
0:03:43	which essentially means now,
0:03:46	router 2 has only one physical path to the rest of the network.
0:03:51	We'll see that router 2 is not gonna learn about any of the other destinations.
0:03:54	Like router 1, or router 3, or router 4,
0:03:57	because when these updates go from these neighbors to 5,
0:04:03	5 is not gonna send an update back to router 2.
0:04:10	So, if we now look at the Show IP Route,
0:04:15	we'll see that a lot of the information in the topology, we do not know about.
0:04:19	So, we don't know how to reach the loopback of router 3, for example.
0:04:24	We don't know how to reach the loopback of router 4.
0:04:27	Okay, we can tell based on the state of router 2's table
0:04:30	that router 5 is using the frame-relay interface to reach those destinations.
0:04:37	These other interfaces, or the other routes that we are learning,
0:04:42	these are the ones that we can infer that in router 5's table, it is not routing out the frame-relay.
0:04:49	So, if I were to trace any of these destinations, like to 155.10.8.8,
0:04:57	router 5 does not send that traffic back out the frame-relay.
0:05:00	Or the 155.10.108.10.
0:05:10	Now, the way that I can infer this based on how the routing table looks
0:05:15	is that again, EIGRP will only advertise what is actually installed in the routing table.
0:05:22	So, whatever router 5 has installed as EIGRP that is via serial 0/0/0,
0:05:34	these are the routes that cannot be advertised to router 2,
0:05:38	because they would be violating the Split Horizon rule.
0:05:41	This likewise means that the alternate paths of these destinations
0:05:48	are not installed via other links.
0:05:51	So, if I were to say, Show IP EIGRP Topology for 150.10.3.0/24,
0:06:01	it actually says, "I have a bunch of possible ways that I could get to this destination,
0:06:07	but not all of these are valid routes."
0:06:11	So, if I were to look at the one that is reachable via router 4's point-to-point link,
0:06:18	It says that the total metric here is 2.3 million,
0:06:23	and the advertised metric is a 161,000.
0:06:29	Now, if we look at what is the total feasible distance,
0:06:32	so what is the lowest end-to-end metric,
0:06:36	we see that this is 2.2 million.
0:06:40	Since this value lower than what router 4's value was.
0:06:46	So, router 4's value is 2.3 million,
0:06:49	it means that this one is not gonna get installed in the routing table.
0:06:53	Since it is not installed in the routing table,
0:06:55	I therefore cannot advertise it,
0:06:57	which means that even thought there's a valid path to reach router 3's loopback this way,
0:07:04	since I'm not installing it on the table, I cannot receive the update in,
0:07:08	and then, advertise it out this direction.
0:07:14	So, the key point here is that depending on the individual state of the topology,
0:07:19	we could have a design where it looks like router 2 has full reachability to the entire network,
0:07:24	but only in the case where router 5 is not using the frame-relay to reach other destinations.
0:07:32	Where in reality, what we should be doing
0:07:35	is just going to router 5's interface,
0:07:38	and saying on...
0:07:40	serial 0/0/0, "I want to disabled Split Horizon for EIGRP process 1."
0:07:53	So now, if we look at the change in router 2's table,
0:07:56	and we Show IP Route EIGRP,
0:08:01	we should see now that router 2 has full routing information for everything that's in the topology.
0:08:10	Now, once the Split Horizon process is disabled,
0:08:14	let's take a look at what the spokes of the network
0:08:18	see as the routes are being learned from router 5.
0:08:23	So, on router 2,
0:08:25	let's look at the Show IP EIGRP Topology All Links.
0:08:36	And specifically, I want to see...
0:08:41	the loopback of router 2.
0:08:46	And...
0:08:49	Actually, I think this is the only connected interface that we're advertising.
0:08:52	Let's look at the Show IP EIGRP Interfaces.
0:09:00	So, it's only this top interface, which is the frame-relay, and then the loopback.
0:09:05	These are the only active links that are being advertised in EIGRP.
0:09:09	So, let's say also on router 2,
0:09:12	I'm gonna advertise the 192.10.10.2 interface.
0:09:19	So, this is router 2's link that connects to BB2.
0:09:26	So, these one here is now being advertised up to router 5.
0:09:30	Since router 5 now has disabled Split Horizon,
0:09:34	we should see the updates goes from 2 to 5,
0:09:37	then from 5 right back to 2.
0:09:42	If we look at the topology, and say Show IP EIGRP...
0:09:46	Topology All Links,
0:09:54	we see that this connected interface
0:09:56	is actually also being learned back from router 5.
0:10:02	Which is fine though, because when we look at the feasible distance of the connected interface,
0:10:09	so, it's basically metric just based on the delay and the bandwidth of the connected Fast Ethernet 0/0,
0:10:17	this would always be lower...
0:10:20	than whatever router 5 could potentially advertise to us.
0:10:26	So, even though there is duplicate routing information,
0:10:29	and we could see this on let's say, router 3.
0:10:32	If we Show IP EIGRP...
0:10:36	Topology All Links.
0:10:41	And we look at let's say...
0:10:45	Switch 1's loopback.
0:10:48	Where switch 1's loopback, this is from router 3's perspective.
0:10:52	Switch 1 advertises this out the directly connected link.
0:10:57	So, router 3 is gonna choose, "This is the best path...
0:11:00	towards that", because it's simply the closest in the topology.
0:11:04	The update goes from 3 to 5.
0:11:07	It goes from 5 back to 3.
0:11:10	When 3 receives this update back in, technically, it is part of the route calculation.
0:11:15	But when we look at the possible paths,
0:11:18	the one that is via switch 1 is always gonna be lower than the other possible routes.
0:11:29	So, the key point being here with Split Horizon,
0:11:32	with EIGRP, it's technically not a loop prevention mechanism.
0:11:35	It's just there to cut down on the amount of useless routes
0:11:39	that you would never use in the first place.
0:11:41	Based on the feasibility condition, the router is always gonna know
0:11:45	who is closer to the destination in the topology.

Now Viewing

CCIE Routing & Switching Advanced Technologies Class
Title:	CCIE Routing & Switching Advanced Technologies Class
Duration:	81h 59m
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.
Get instant access to our entire library!
$159/month	Add to Cart
Download this Course
$299.00	Add to Cart

EIGRP Split-Horizon

Create Bookmark