Internet Light Issue

[#1]

Hey guys,
A little while ago, my connection dropped so I reset the router by turning it off and on again. Now it is up again, we have internet access but the internet light on the router is still not lit. What does this mean?

[#2]

It may be worth noting that some websites and services do not work as they once did since this issue, yet others work fine.

[#3]

Problems with accessing specific websites can be cause by MTU mismatch between the router and PC. Is the MTU on the router smaller than that on the PC? The latter is likely to by 1500.
Alternatively does your PC use the router to supply DNS? What does ipconfig /all entered at a command prompt show?

[#4]

Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.
C:\Users\Scratch>ipconfig /all
Windows IP Configuration
  Host Name . . . . . . . . . . . . : Ratpants
  Primary Dns Suffix  . . . . . . . :
  Node Type . . . . . . . . . . . . : Hybrid
  IP Routing Enabled. . . . . . . . : No
  WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection:
  Connection-specific DNS Suffix  . :
  Description . . . . . . . . . . . : Realtek RTL8168B/8111B Family PCI-E Gigab
it Ethernet NIC (NDIS 6.20)
  Physical Address. . . . . . . . . : 00-22-68-56-A8-8B
  DHCP Enabled. . . . . . . . . . . : Yes
  Autoconfiguration Enabled . . . . : Yes
  Link-local IPv6 Address . . . . . : fe80::d5d8:80bc:3a97:2565%11(Preferred)
  IPv4 Address. . . . . . . . . . . : 192.168.0.4(Preferred)
  Subnet Mask . . . . . . . . . . . : 255.255.255.0
  Lease Obtained. . . . . . . . . . : 20 March 2011 11:29:01
  Lease Expires . . . . . . . . . . : 21 March 2011 11:29:01
  Default Gateway . . . . . . . . . : 192.168.0.1
  DHCP Server . . . . . . . . . . . : 192.168.0.1
  DHCPv6 IAID . . . . . . . . . . . : 234889832
  DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-14-F9-C1-74-00-22-68-56-A8-8B
  DNS Servers . . . . . . . . . . . : 192.168.0.1
  NetBIOS over Tcpip. . . . . . . . : Enabled
Tunnel adapter isatap.{50C92EDA-7F80-4034-AB01-63C6EF259914}:
  Media State . . . . . . . . . . . : Media disconnected
  Connection-specific DNS Suffix  . :
  Description . . . . . . . . . . . : Microsoft ISATAP Adapter
  Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
  DHCP Enabled. . . . . . . . . . . : No
  Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Local Area Connection* 11:
  Connection-specific DNS Suffix  . :
  Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
  Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
  DHCP Enabled. . . . . . . . . . . : No
  Autoconfiguration Enabled . . . . : Yes
  IPv6 Address. . . . . . . . . . . : 2001:0:5ef5:79fd:34af:16c6:a88c:770c(Pref
erred)
  Link-local IPv6 Address . . . . . : fe80::34af:16c6:a88c:770c%12(Preferred)
  Default Gateway . . . . . . . . . : ::
  NetBIOS over Tcpip. . . . . . . . : Disabled
C:\Users\Scratch>

[#5]

Quote from: scratchrat

DNS Servers . . . . . . . . . . . : 192.168.0.1

The router is being used to provide DNS, only an issue if the router is having lookup problems with its own source (presumably Plusnet DNS).
The MTU on your computer can be found as described on this page (Kitz); ie run
netsh interface ipv4 show subinterfaces at a command prompt.
The router MTU should be shown somewhere on the web interface but a useful check is to do
ping -f -l 1472 ntp.plus.net Packets will fragment if the router MTU is less than 1500.
Working down in 10s is recommended to determine when fragmentation stops, then up in 1s or 2s to find the limit.
MTU is this value + 28
Se Kitz's page here for more on MTU and discussion of some websites failing to load.