Ccna routing and Switching Complete Study Guide

ipv6 access-list Block_Telnet

R2(config-ipv6-acl)#

Step 3: Once you have created the named list, add your test parameters.

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Chapter 20 

■

  Troubleshooting IP, IPv6, and VLANs

R2(config-ipv6-acl)#

deny tcp host 2001:DB8:3C4D:2:21A:6DFF:FE37:A44F host 

2001:DB8:3C4D:1:A14C:8C33:2D1:BE3D eq telnet

R2(config-ipv6-acl)#

permit ipv6 any any

Step 4: Configure your ACL on your router interface.

Since we’re adding this to the R2 router in Figure 20.4, we’ll add it to interface 

FastEthernet 0/1, stopping traffic closest to the source, and use the command 

ipv6 

traffic-filter

.

R2(config)#

int fa0/1

R2(config-if)#

ipv6 traffic-filter Block_Telnet out

Step 5: Test your access list by telnetting from Server1 on the R1 router.

R1#

Server1

Trying 2001:DB8:3C4D:1:A14C:8C33:2D1:BE3D ...Open

 

 

Server1>

Hmm… and I tried really hard not to make a typo! Let’s take a look.

R2#

sh access-lists

IPv6 access list Block_Telnet

      deny tcp host 2001:DB8:3C4D:2:21A:6DFF:FE37:A44F host  

2001:DB8:3C4D:1:A14C:8C33:2D1:BE3D eq telnet (96 match(es))

      permit ipv6 any any (181 match(es))

By verifying the IPv6 addresses with the interfaces of the routers, this list looks correct. 

It’s important to verify your addresses with a 

show ipv6 interface brief

 command. Let’s 

take a look.

R1#