CCNP SWITCH/Implementing Inter-VLAN Routing - Revision history

Heth at 07:24, 13 November 2011

2011-11-13T07:24:11Z

Rael: /* CEF Troubleshooting */

2011-08-30T06:45:49Z

‎CEF Troubleshooting

Rael at 06:12, 30 August 2011

2011-08-30T06:12:01Z

Rael: /* TCAM Layout */

2011-08-29T17:53:19Z

‎TCAM Layout

Rael: /* CAM and TCAM Tables */

2011-08-29T17:52:46Z

‎CAM and TCAM Tables

Rael: /* ARP Throttling */

2011-08-29T13:24:34Z

‎ARP Throttling

Rael: /* TCAM Layout */

2011-08-29T13:20:20Z

‎TCAM Layout

Rael: /* Deploying CEF-Based Multilayer Switching */

2011-08-29T12:38:24Z

‎Deploying CEF-Based Multilayer Switching

Rael: /* Verify DHCP Operation */

2011-08-29T10:29:17Z

‎Verify DHCP Operation

Rael: /* Implementing Dunamic Host Configuration Protocol in a Multilayer Switched Environment= */

2011-08-29T10:27:24Z

‎Implementing Dunamic Host Configuration Protocol in a Multilayer Switched Environment=

← Older revision		Revision as of 07:24, 13 November 2011
Line 275:		Line 275:
	show adjacency gigabitethernet 1/5 detail<br/>		show adjacency gigabitethernet 1/5 detail<br/>
	{{Source cli}}		{{Source cli}}
		+	[[Category:Cisco]][[Category:CCNP]]

← Older revision		Revision as of 06:45, 30 August 2011
Line 274:		Line 274:
	show adjacency<br/>		show adjacency<br/>
	show adjacency gigabitethernet 1/5 detail<br/>		show adjacency gigabitethernet 1/5 detail<br/>
		+	{{Source cli}}

← Older revision		Revision as of 06:12, 30 August 2011
Line 1:		Line 1:
−	~~{{In progress}}~~
	=Inter-VLAN Routing=		=Inter-VLAN Routing=
	Because VLANs isolate trafficto a defined broadcast domain and subnet, network devices in different VLANs cannot communicate with each other natively.		Because VLANs isolate trafficto a defined broadcast domain and subnet, network devices in different VLANs cannot communicate with each other natively.

@@ Line 230: / Line 230: @@
 | IP adjacency || ip-adjacency || Exact-Match || 32 bits || MAC address rewrite information
 |-
-| IP prefix || ip-prefix || Longest-match || 32 bit || Next-hop routing information
+| IP prefix || ip-prefix || Longest-match || 32 bits || Next-hop routing information
 |-
 | IP multicast || ip-mcast || Longest match || 64 bits || Next-hop Routing information

@@ Line 205: / Line 205: @@
 ;CAM table
 :The primary table used to make Layer 2 forwarding decisions. The table is built by recording the source MAC address and inbound port of all incoming frames. When a frame arrives at the switch with a destination MAC address of an entry in the CAM table, the frame is forwarded out through only the port that is associated with that specific MAC address.
 {|
 |[[Image:ScreenShot387.jpg|800px|left|thumb|CAM]]
 |}
 {|
 |[[Image:ScreenShot388.jpg|800px|left|thumb|TCAM]]
@@ Line 240: / Line 240: @@
 |Access lists || access-list || First-match || 128 bits || Permit, deny, or wildcard
 |}
 ==Distributed Hardware Forwarding==
 {|

← Older revision		Revision as of 13:24, 29 August 2011
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	==ARP Throttling==		==ARP Throttling==
	he ARP throttling adjacency drops the first packet in any communication between due to ARP processing when no ARP entries exist for the Hosts.		he ARP throttling adjacency drops the first packet in any communication between due to ARP processing when no ARP entries exist for the Hosts.
		+	=CEF Troubleshooting=
		+	show ip cef vlan 10 detail<br/>
		+	show adjacency<br/>
		+	show adjacency gigabitethernet 1/5 detail<br/>

← Older revision		Revision as of 13:20, 29 August 2011
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	\|Access lists \|\| access-list \|\| First-match \|\| 128 bits \|\| Permit, deny, or wildcard		\|Access lists \|\| access-list \|\| First-match \|\| 128 bits \|\| Permit, deny, or wildcard
	\|}		\|}
		+	==Distributed Hardware Forwarding==
		+	{\|
		+	\|[[Image:ScreenShot392.jpg\|800px\|left\|thumb\|hardware forwarding overview]]
		+	\|}
		+	==Cisco Switching Methods==
		+	;Process Switching
		+	:In process switching, the router strips off the Layer 2 header for each incoming frame, looks up the Layer 3 destination network address in the routing table for each packet.
		+	;Fast Switching
		+	:After the lookup of the first packet destined for a particular IP network, the router initializes the fast-switching cache used by the Fast switching mode.
		+	;Cisco Express Forwarding (CEF)
		+	:The default-switching mode. CEF is less CPU-intensive than fast switching or process switching.
		+	===CEF modes of operation===
		+	*Central CEF mode
		+	*Distributed CEF mode(dCEF)
		+	==CEF Processing==
		+	{\|
		+	\|[[Image:ScreenShot1112.jpg\|800px\|left\|thumb\|CEF]]
		+	\|}
		+	The FIB contains a pointer to the Adjacency table with rewrite information.<br/>
		+	The point could also point to these special adjacencies:
		+	;Punt adjacency
		+	:Usedfor packets that require special handling by the Layer 3 engine or for features that are not yet supported by hardware switching.
		+	;Drop or discard adjacency
		+	:Used to drop ingress packets.
		+	;Null adjacency
		+	:Used to drop packets destined for a Null0 interface. The use of a Null0 interface is for access filtering of specific source IP packets.
		+	;Glean adjacency
		+	:When no rewrite information exists the switch needs to make an ARP.
		+	==ARP Throttling==
		+	he ARP throttling adjacency drops the first packet in any communication between due to ARP processing when no ARP entries exist for the Hosts.

← Older revision		Revision as of 12:38, 29 August 2011
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	</source>		</source>
	=Deploying CEF-Based Multilayer Switching=		=Deploying CEF-Based Multilayer Switching=
		+	Layer 3 switching provides a wire-speed mechanism by which to route packets between VLANs using tables that store Layer2 and Layer3 forwarding information in the hardware.<br/><br/>
		+	A Layer 3 switch performs three major functions:
		+	*Packet Switching
		+	*Route Processing
		+	*Intelligent network services
		+	Frame Rewrite:
		+	{\|
		+	\|[[Image:ScreenShot386.jpg\|800px\|left\|thumb\|Checksum calculation and rewrite.]]
		+	\|}
		+	==CAM and TCAM Tables==
		+	;CAM table
		+	:The primary table used to make Layer 2 forwarding decisions. The table is built by recording the source MAC address and inbound port of all incoming frames. When a frame arrives at the switch with a destination MAC address of an entry in the CAM table, the frame is forwarded out through only the port that is associated with that specific MAC address.
		+	;TCAM table
		+	:Stores ACL, QoS, and other information generally associated with Layer 3 and up layer processing.
		+	{\|
		+	\|[[Image:ScreenShot387.jpg\|800px\|left\|thumb\|CAM]]
		+	\|}
		+	{\|
		+	\|[[Image:ScreenShot388.jpg\|800px\|left\|thumb\|TCAM]]
		+	\|}
		+	===TCAM Layout===
		+	The TCAM is devided into several regions such as one for ACL, one for multicast and one for IP-PREFIX.<br/><br/>
		+	The regions have these lookup types:
		+	;Exact-match region
		+	:Consistsof Layer 3 entries for regions such as IP adjacencies. IP adjacencies are the next-hop information (MAC address) for an IP address. Other examples of exact-match regions are Layer 2 switching tables and UDP flooding tables.
		+	;Longest-match region
		+	:Consistsof multiple “buckets” or groups of Layer 3 address entries organized in decreasing order by mask length. All entries within a bucket share the same mask value and key size. The buckets change their size dynamically by borrowing address entries from neighboring buckets. Although the size of the whole protocol region is fixed, as mentioned in Table 4-4, several platforms support configuration of the region size. For most platforms, the reconfigured size of the protocol region is effective only after the next system reboot.
		+	;First-match region
		+	:Consists of regions that stop lookups after the first match of the entry. An example of when a first-match region is used is for ACL entries.
		+
		+	{\| class="wikitable sortable" style="text-align:center" border=1
		+	\|+ Common TCAM Protocol Regions
		+	\|- bgcolor=lightgrey
		+	! Region name !! Cisco IOS Region Name !! Lookup Type !! Key Size !! Sample result
		+	\|-
		+	\| IP adjacency \|\| ip-adjacency \|\| Exact-Match \|\| 32 bits \|\| MAC address rewrite information
		+	\|-
		+	\| IP prefix \|\| ip-prefix \|\| Longest-match \|\| 32 bit \|\| Next-hop routing information
		+	\|-
		+	\| IP multicast \|\| ip-mcast \|\| Longest match \|\| 64 bits \|\| Next-hop Routing information
		+	\|-
		+	\| Layer 2 switching \|\| l2-switching \|\| Exact-match \|\| 64 bits \|\| Destination interface and VLAN
		+	\|-
		+	\| UDP flooding \|\| udp-flooding \|\| Exact-match \|\| 64 bits \|\| Next-hop routing og MAC address rewrite information
		+	\|-
		+	\|Access lists \|\| access-list \|\| First-match \|\| 128 bits \|\| Permit, deny, or wildcard
		+	\|}

← Older revision		Revision as of 10:29, 29 August 2011
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	DHCPD: broadcasting BOOTREPLY to client 001b.d513.2ad2.		DHCPD: broadcasting BOOTREPLY to client 001b.d513.2ad2.
	</source>		</source>
		+	=Deploying CEF-Based Multilayer Switching=

@@ Line 142: / Line 142: @@
 Switch(config-if)# <input>ip summary-address eigrp 100 10.1.0.0 255.255.240.0</input>
 </source>
-=Implementing Dunamic Host Configuration Protocol in a Multilayer Switched Environment==
+=Implementing Dunamic Host Configuration Protocol in a Multilayer Switched Environment=
 As defined in RFC 2131, Dynamic Host Configuration Protocol (DHCP) provides configuration parameters to Internet hosts.