Internet Connection issue between Router and Switch

[cyberhunt]

Hi Everyone,

I hope someone can help me. I try to setup my router and switch and I am a little bit stuck.

I have sort of internet connection on my router but not on the switch. I can ping 8.8.8.8 on the router but 2 or 3 out of the 5 packets go through and the others drop.

Can someone please have a look at my configs and tell me where did I go wrong and also if the configs can be brush up a bit.

Thank you in advance.

[Richard Burts]

I note 2 things in the configuration of the router.

1) the configuration of address translation uses an access list identified as NAT. But there is no acl NAT in the configuration. There is an acl 1 which would work nicely. To fix the issue either configure an acl NAT or change the nat configuration to use acl 1. (my suggestion is to use acl 1). I believe this is the major issue impacting your Internet access.

2) your static default route specifies the outbound interface, but not any next hop. There are several reasons why this is not a good idea, especially if the outbound interface is Ethernet. The most important aspect is that this configuration forces the router to arp for every remote destination and depends on the next hop device to support proxy arp. Since you are able to ping 8.8.8.8 from the router it appears that your next hop does support proxy arp. The other issues do not cause anything to fail but do impact performance and they include that the router arp table will have an entry for EVERY remote destination address (so memory consumption might have an impact), maintaining the arp table requires that every 4 hours the router refresh the entry (so there is cpu activity to generate the requests, and bandwidth is consumed to send requests and receive responses). 

I do not see any particular issues in the switch config, but I do note that it looks like vlan 20 does not have an entry in the vlan data base, and that there are no access ports in vlan 20.

[cyberhunt]

But there is no internet connectivity on the switch side. Is there a way for you to adjust the router config and upload it so that I can see an example of it. My next hop is a normal home router that I connected to the outbound interface. Regarding the vlan 20 I am going to add a WLC which will then be using it.

Thank you in advance.

[Richard Burts]

Lack of Internet connectivity on switch is due to problems with NAT on the router. I have provided suggestions on how to fix this.

[cyberhunt]

Ok can you then point me in the right direction to fix the NAT.