Packet Tracer DHCP Server and Router SLAAC not leasing IP

[mattbra]

Hello, could someone take a look at my packet tracer?

I'm triying to solve the packet tracer from my teacher but I can't make the DHCP Server lease IP address because in simulation mode, in the layer 7 it says "The DHCP server does not have a pool configured for the received port. It drops the packet." But the Server came already configured with the .pkt

And, I'm trying to make work SLAAC with DHCPv6 on (R0) to serve Router Advertisements to clients.

The point is that my clients (HR0) and (HR1) are routers, all of them in the same network but separated by modems and to make them clients I'm using these commands:

!

int g0/0

ip address dhcp

ipv6 address autoconfig

But it doesn't seem to work properly, can someone give me a hint or tell me where is the problem or what is the cause?

I uploaded the .pkt

Thanks, 

Matt

[Martin L]

not sure if that SLAAC  over modems works in PT. Check in samples files that come with PT.

Regards, ML
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[Harold Ritter]

Hi @Martin L ,

What seems to be not supported in PT is the router auto configuring its interface using SLAAC, as putting a PC in place of the router works just fine.

Regards,

[mattbra]

Guess you are right but I've watching tutorials, especially one about "Lab 3. IPv6 Address Autoconfiguration" in YouTube and it worked with PT and GS3. Anyways thanks for the info 

[Harold Ritter · Accepted solution]

Hi @mattbra ,

I got it to work with the 1941 in your topology using the following procedure.

HR0:

config t

int gi0/0

shut

no ipv6 address 

ipv6 enable

ipv6 address FE80::2 link-local

ipv6 address autoconfig

no shut

Regards,

[mattbra]

Ohhh, yes this!!

I was missing the

ipv6 enable

command on the interface Gi0/0

Also, I cheked it with

debug ipv6 nd

and on HR0 I needed to have

ipv6 unicast-routing on global config and ipv6 address autoconfig and ipv6 enable

on the interface to start configuring the prefix from RA messages from the Router sending the RA.

But, why do you need

ipv6 unicast-routing and ipv6 enable

to get the router auto configuring its interface using SLAAC?

HR0 auto configuring its interface Gi0/0

Because if I don't enable

ipv6 unicast-routing and I just have ipv6 address autoconfig and ipv6 enable

I get:

HR0 doesn't auto configure its interface

[Harold Ritter]

Hi @mattbra ,

>But, why do you need

ipv6 unicast-routing and ipv6 enable

to get the router auto

> configuring its interface using SLAAC?

I think this is just a PT implementation issue. in IOS, you do not need to configure

ipv6 uni cast-routing

if you want the IOS to act as a host and the

ipv6 address autoconfig

would still work. The other thing I noticed is that if you exit PT and reload,

ipv6 address autoconfig

will not work and I needed to reapply the script I suggested in my previous to get it to work again. Ate the end of the day, PT is a very good simulation tool, but often reacts very differently than IOS.

Regards,

[mattbra]

PT is a good tool for me, I don't have any physical Cisco equipment to test, but I will be more aware from now on that it may not always simulate everything correctly. I also noticed what you mentioned, when you close PT you have to reapply the configuration to the interface.

Thanks @Harold Ritter 

Matt. 

[mattbra]

I checked the sample files and the routers doesn't get the config with SLAAC but PC does get it.

[Harold Ritter · Accepted solution]

Hi @mattbra ,

As far as DHCP is concerned, the issue is that the pool homes start address is 10.64.1.100 instead of 100.64.1.100.

Regards,

[mattbra]

Got it, thanks!!