I recently got almost brand new Cisco 2911 router and Cisco 2960 switch for free from school. I've been configuring both a little bit in school so I can handle the basic stuff. I currently live in an older apartment where a coaxial cable comes into ISP's provided router. The router also happens to be a Cisco device (Cisco EPC3825). This router is wireless with four ethernet ports. Now, 2911 does not have a coaxial input so I have to put ISP's router before Cisco 2911 in my setup. This setup will be a temporary one and I am just testing how things work out. I am moving sooner to a newer apartment where there will be ethernet ports in the walls so I can move my ISP's router behind 2911.
I know my public IP address and ISP's provided gateway and DNS-servers. Currently ISP's router's LAN IP is 192.168.1.1. I connected from first ethernet port of the ISP's router into 2911's GigabitEthernet0/0 port. I gave an IP address of 192.168.1.2 to the 2911's 0/0 port. From GigabitEthernet0/1 goes ethernet cable into my 2960 switch and from there on it goes to my desktop machine and server machine. In the future I connect the ISP's router into the 2960. Currently I haven't made any changes into ISP's router's settings. They are pretty much factory defaults.
The network I have given to my LAN devices behind 2911 is 172.17.1.0/24. The 2911's 0/1 port has IP address of 172.17.1.1. The 2960 switch has IP address of 172.17.1.2. I installed a DHCP server on the 2911 router and when I connect my laptop into the switch it gives me an IP address from 172.17.1.10-172.17.1.250 area. Now I can ping from laptop the 2960 switch, 2911 router's both ports and the ISP's router. But then I cannot ping google's public DNS (188.8.131.52) nor ISP's provided gateway for example. I have desktop computer plugged straight into ISP's router, and internet works very well from there. Also if I connect my laptop via wireless into the ISP's router, internet works very well. But from either setup (desktop into ISP router or laptop via wireless into ISP router) I can only ping Cisco 2911's 0/0 port but not behind that. From the 2911 itself I cannot ping to either laptop nor desktop machine even when they have their firewalls off.
Here is the config of the 2911 router:
Current configuration : 1528 bytes ! version 15.4 service timestamps debug datetime msec service timestamps log datetime msec service password-encryption ! hostname Router ! boot-start-marker boot-end-marker ! ! ! no aaa new-model ! ! ! ! ! ! ! ! ! ! ! ip dhcp excluded-address 172.17.1.1 172.17.1.10 ! ip dhcp pool LAN_POOL network 172.17.1.0 255.255.255.0 default-router 172.17.1.1 dns-server 184.108.40.206 220.127.116.11 lease 7 ! ! ! ip cef no ipv6 cef multilink bundle-name authenticated ! ! cts logging verbose ! ! ! ! ! redundancy ! ! ! ! ! ! interface Embedded-Service-Engine0/0 no ip address shutdown ! interface GigabitEthernet0/0 ip address 192.168.1.2 255.255.255.0 ip nat outside ip virtual-reassembly in duplex auto speed auto ! interface GigabitEthernet0/1 ip address 172.17.1.1 255.255.255.0 ip nat inside ip virtual-reassembly in duplex auto speed auto ! interface GigabitEthernet0/2 no ip address shutdown duplex auto speed auto ! ip forward-protocol nd ! no ip http server no ip http secure-server ! ip nat inside source list 23 interface GigabitEthernet0/0 overload ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 ! ! ! access-list 23 permit 172.17.1.0 0.0.0.25 ! control-plane ! ! ! line con 0 password 7 091D1C5A4A11141E login line aux 0 line 2 no activation-character no exec transport preferred none transport output pad telnet rlogin lapb-ta mop udptn v120 ssh stopbits 1 line vty 0 4 password 7 0257560858120C2D login transport input none ! scheduler allocate 20000 1000 ! end
As you can see from the configs I have tried to add static routing and playing with the NAT, neither one giving any results. What I am trying to achieve here is to connect to internet behind 2911 router, and to connect from internet to my server machine behind 2911 router. The solution may be simple but I just can't see it.