topic Ping not working in Broadband

Ping not working

JohnAaronRose — Wed, 15 Nov 2023 09:01:49 GMT

When i try to ping my ip address as shown as shown in the 'Internet Connectivity' admin web page all packets get lost. Why is that?

Re: Ping not working

KeithFrench — Wed, 15 Nov 2023 10:19:10 GMT

Do you mean the IP address of your device, the router's private or public one?

Re: Ping not working

JohnAaronRose — Wed, 15 Nov 2023 10:35:23 GMT

I can ping the Gateway (92.30.64.1) but not the Public IP Address ( 92.30.75.195). Not sure what you mean by the private IP address: is it the IP address of the LAN (i.e. 192.168.1.1)?

Re: Ping not working

KeithFrench — Wed, 15 Nov 2023 10:44:37 GMT

The private IP addresses are the ones on the device side of the router (default of the 192.168.1.0 network). You can't ping the router's WAN IP address because of two reasons:-

Incoming PING requests are not normally allowed by the firewall, for your privacy.
NAT loopback blocks any packet being sent from the private side of the router, out to the internet & back in, as it is considered a security risk.

Re: Ping not working

KeithFrench — Wed, 15 Nov 2023 10:49:34 GMT

I have just proved that whilst NAT Loopback might have an impact if the firewall allowed PINGs, it is the firewall that is blocking this in the first instance.

Re: Ping not working

JohnAaronRose — Wed, 15 Nov 2023 11:13:16 GMT

Even when I modify the Firewall in the Sagem 5364 Router: 'Respond to Ping' to On and Level to Medium, ping still does not 'find' the Public IP Address ( 92.30.75.195). Why is that?

Before I had Fibre (upgraded in last week), broadband was done by copper line all the way from the Cabinet to the Property and ping worked OK.

Re: Ping not working

KeithFrench — Wed, 15 Nov 2023 11:19:03 GMT

It is very common for any router or firewall to block PINGs these days. It is probably something to do with the full fibre network that you are on.

Re: Ping not working

KeithFrench — Wed, 15 Nov 2023 11:31:56 GMT

Hi @henryhawthort

If you want help, you cannot use someone else's thread.

To get help, you must start your own thread. To create your own thread, go to the main page for the board in question & click the "Start a topic" button.

TalkTalk insists on one thread per problem per customer. Please note, TalkTalk makes the rules, not me.

Thanks.

Re: Ping not working

JohnAaronRose — Wed, 15 Nov 2023 12:03:51 GMT

I'm on FTTC not FTTP: so not full fibre. Homes in my town (Wolverhampton) are currently being upgraded this way.
I still don't understand why "Even when I modify the Firewall in the Sagem 5364 Router: 'Respond to Ping' to On and Level to Medium, ping still does not 'find' the Public IP Address ( 92.30.75.195). Why is that?".

I'm not really concerned so much by the Ping not 'found' of the Router's public IP address as my home web site (on an attached Raspberrey Pi) gets a 404 when it used to work before this Fibre upgrade.

Re: Ping not working

KeithFrench — Wed, 15 Nov 2023 12:56:24 GMT

As I said it is either down to a router in the TalkTalk network blocking them, before they arrive back at your router or NAT Loopback.

Re: Ping not working

JohnAaronRose — Wed, 15 Nov 2023 13:25:06 GMT

I don't understand about the router. Presumably you mean a router in TalkTalk's own network (rather my LAN as attached to TalkTalk's Sagem 5364 router which is in my property).

As I said before, "I'm not really concerned so much by the Ping not 'found' of the Router's public IP address as my home web site (on an attached Raspberrey Pi) gets a 404 when it used to work before this Fibre upgrade. So How to get my web server to serve up web pages?

Re: Ping not working

KeithFrench — Wed, 15 Nov 2023 13:27:21 GMT

The internet is made up of goodness knows how many routers, some within TalkTalk's network, some belonging to other ISPs and the backbone that makes up the internet. Any one of these 1000's of routers could be blocking PINGs. NAT Loopback refers to your 5364 router.

Sorry, but there is nothing that you can do about this at all.

Re: Ping not working

JohnAaronRose — Wed, 15 Nov 2023 14:06:26 GMT

Re: Ping not working

KeithFrench — Wed, 15 Nov 2023 14:52:23 GMT

That is a different issue altogether. Have you set up the required port forwarding in the router (don't touch its firewall)? Then, if it has one, you will need to allow these ports through any firewall on the Raspberrey Pi?

Re: Ping not working

gmlack — Wed, 15 Nov 2023 15:46:45 GMT

You can find your external address by visiting:

https://myexternalip.com/

which will display it at the top.

As for serving up you own web pages, you'll need to set up port mapping to get through your router.
And if you want to use a name (rather than a - changing - IP address) you'll need to use a service such as DynDNS, No-IP (there are lots of them...look for Dynamic DNS services).

Re: Ping not working

JohnAaronRose — Wed, 15 Nov 2023 16:14:48 GMT

The TalkTalk's Sagem 5364 router has WiFi turned off with only one Wired RJ45 connection to my TP-Link router and all services required (e.g. 80 & 443) Port Forwarded to my TP-Link router. The TP-Link router has all required services (e.g. 80 & 443) Port Forwarded to my Raspberry Pi. My Raspberry Pi has all required services (e.g. 80 & 443) allowed in ipTables i.e. no change from when it worked pre-Fibre.

Re: Ping not working

KeithFrench — Wed, 15 Nov 2023 16:18:10 GMT

How are you testing this? It is highly likely that after your upgrade you have a new WAN IP address, but then I guess you have taken that into account by trying to ping it. Does your Raspberry Pi support Wireshark or any other pcap capture tools?

Re: Ping not working

gmlack — Thu, 16 Nov 2023 00:04:14 GMT

"...gets a 404 when it used to work before..."

A 404 implies that it got to a Web server somewhere. Inability to get to a server would surely result in a timeout.

Re: Ping not working

JohnAaronRose — Thu, 16 Nov 2023 05:50:12 GMT

I've installed wireshark on my Pi.. Running it on my wired interface (eth0) on the Pi shows that there is no tcp (or even udp) messages for the wired interface from my TP-Link router to the Pi. Strangely, even though I selected a directory on my Pi. So I've attached a screenshot of wireshark showing the messages. Please ignore the VNC ones and the TCP 5900 & 49024 ones as I control the Pi from my Desktop using VNC. 192.168.2.10 is the reserved NAT address for my Pi. I don't see 192.168.2.108 on my TP-Link router's DHCP Client List.

I don't see any way that I can check the messages to & from the TalkTalk Sagem router or to & from my TP-Link router. Any ideas on that?
PS I misinformed earlier about the response for my web site: I didn't get a 404 but eventually a timeout.

Re: Ping not working

KeithFrench — Thu, 16 Nov 2023 08:48:42 GMT

Due to the vast information that a Wireshark trace contains, a screenshot is of no use. Please save it as a trace, zip it up & attach it to your thread.

Are all IP interfaces involved in the port forwarding still correct, are they static or DHCP reserved addresses?