New Router, Small Problem

[mmartell]

I upgraded to a wireless AC router and everything seems to work fine except, well, I'm sure there's proper nomenclature to describe it but it's over my head so I'll do my best.

I can no longer login to RDP (Remmina on Ubuntu) using the Windows pc hostnames - using the IP address works fine. I reinstalled the old router briefly to prove to myself I wasn't imagining things and it worked as expected.

I know there are workarounds for this but am more curious as to WHY this stopped working with the new router as I would have expected Name Resolution on all routers.

I don't see any setting in the router (Tenda AC15) that would affect this, am I missing something ?

[jondoe]

Re: New Router, Small Problem

Hostnames require a DNS entry, some where, your old router might have assigned them somehow, which is why hostname lookups not longer work but direct IP's do.

[jiroy]

Re: New Router, Small Problem

One easy way to bypass such problems is , to erase references to previous networks , meaning , open "Network and sharing center" , then ===> "Manage wireless networks" , then right click and remove all Networks existing , including the new ones , then add the New one ...

[mmartell]

Re: New Router, Small Problem

Hostnames require a DNS entry, some where, your old router might have assigned them somehow, which is why hostname lookups not longer work but direct IP's do.

These DNS entries were stored on the router itself ?

[mmartell]

Re: New Router, Small Problem

One easy way to bypass such problems is , to erase references to previous networks , meaning , open "Network and sharing center" , then ===> "Manage wireless networks" , then right click and remove all Networks existing , including the new ones , then add the New one ...

The computer I'm trying to connect to is on Win7 and I don't see "Manage Networks" (It's on a lan).

[jiroy]

Re: New Router, Small Problem

The computer I'm trying to connect to is on Win7 and I don't see "Manage Networks" (It's on a lan).

(It's on a lan) knocks off my method . It's good for a direct wireless to wireless access points .

I don't remember other methods for your Lan , but i think opening a "new connection 2" might solve the problem .

[retiredcaps]

Re: New Router, Small Problem

These DNS entries were stored on the router itself ?

Yes, you or someone else might have manually entered this into the old router.

It would look something like

192.168.1.45 Ubuntu_PC

It is likely that your PC's DNS server is pointing to 192.168.1.1 (the new router). If the new router can't resolve it locally, it sends to the ISP DNS server.

[mmartell]

Re: New Router, Small Problem

It is likely that your PC's DNS server is pointing to 192.168.1.1 (the new router). If the new router can't resolve it locally, it sends to the ISP DNS server.

THIS

Where is that information stored in Ubuntu ? My new router points to a different address, yes.

Maybe I should change it manually to the old address and see if that solves it...

[retiredcaps]

Re: New Router, Small Problem

@mmartell, what is the old router make and model?

On your new router, I can't see anything in the documentation, from a brief glance, that allows you to do any manual entries of hostname to IP address mapping.

I use lede 17.01.1 sw (open source) on my routers that support it and it has a feature to allow me to add manual entries of hostname to IP address mapping.

https://lede-project.org/

I use lede or openwrt because eventually the consumer router vendor will stop updating its software and will have some exploit in the future.

With openwrt or lede, it does get updates about every 4 to 6 months.

[retiredcaps]

Re: New Router, Small Problem

Where is that information stored in Ubuntu ?

On mine Lubuntu system

$ cat /etc/resolv.conf
# Generated by resolvconf
nameserver 192.168.1.1

This tells me that this PC (1) uses the router (2), 192.168.1.1, for name resolution. In my case, the router's DNS entry is my local ISP (3).

Alternatively, I can make the PC or my router use another DNS server like Google (3) (8.8.8.8) or OpenDNS (3).

However, neither Google (3), the local ISP (3) or OpenDNS (3) will know about your local hosts naming convention. It is up to you to input this information locally either into your local router (2) or each PC's local hosts file (1).

edit: added a picture and numbering to hopefully make this clearer for you.

[retiredcaps]

Re: New Router, Small Problem

BTW, the latest firmware is

AC15 Firmware V15.03.1.17_EN

As a rule, I always run the latest firmware for bug fixes and possible patched security vulnerabilities.

[mmartell]

Re: New Router, Small Problem

@mmartell, what is the old router make and model?

On your new router, I can't see anything in the documentation, from a brief glance, that allows you to do any manual entries of hostname to IP address mapping.

I use lede 17.01.1 sw (open source) on my routers that support it and it has a feature to allow me to add manual entries of hostname to IP address mapping.

https://lede-project.org/

I use lede or openwrt because eventually the consumer router vendor will stop updating its software and will have some exploit in the future.

With openwrt or lede, it does get updates about every 4 to 6 months.

Old router was Asus RT-N56u Before that was a Cisco E4200v2 (can't use dd-wrt on it)

[mmartell]

Re: New Router, Small Problem

On mine Lubuntu system

$ cat /etc/resolv.conf
# Generated by resolvconf
nameserver 192.168.1.1

This tells me that this PC (1) uses the router (2), 192.168.1.1, for name resolution. In my case, the router's DNS entry is my local ISP (3).

Alternatively, I can make the PC or my router use another DNS server like Google (3) (8.8.8.8) or OpenDNS (3).

However, neither Google (3), the local ISP (3) or OpenDNS (3) will know about your local hosts naming convention. It is up to you to input this information locally either into your local router (2) or each PC's local hosts file (1).

edit: added a picture and numbering to hopefully make this clearer for you.

Nothing applicable at that location in Ubuntu 16.04

I understand how DNS works for internet traffic but not really how it's implemented for local machines (for which an external DNS server will have no knowledge) I have never input addresses manually into a dns cache either on the pc or on the router before so not sure how they got cached in the first place ?

Also, If I RDP from another windows machine TO another windows machine on my lan it works fine.

So how do these get cached without user input ?

[mmartell]

Re: New Router, Small Problem

BTW, the latest firmware is

AC15 Firmware V15.03.1.17_EN

As a rule, I always run the latest firmware for bug fixes and possible patched security vulnerabilities.

Ran the online upgrade via the router after unboxing and current version moved to V15.03.05.07_multi. Current version as reported by the router today.

[jondoe]

Re: New Router, Small Problem

Some routers are DNS servers and DHCP servers combined, when a PC/device does a DNS lookup at the router, the router responds and the IP is resolved to the hostname via the routers DNS records. Many routers do this so if the internet connection goes down, it routes back to a help page/setup page, etc, on the router itself .

When your PC/device has external DNS servers configured, it won't know the hostnames for your local devices.

[mmartell]

Re: New Router, Small Problem

It's bizarre because every entry in the DHCP list has a name associated with it and an IP address underneath the name - like the feature just needs to be enabled.

[eccerr0r]

Re: New Router, Small Problem

Type 1: Some router firmware accepts the DHCP hostname as a hostname and uses its internal DNS cache to point hostname lookups to this LAN host.

Type 2: Some router firmware allows you to do MAC address static IP hosts which you have to configure through the web pages.

Type 3: Some router firmware does neither, and you'll never be able to refer to LAN computers by name.

I'd imagine the cheaper routers go to type 3 like the Tenda. I've only recalled one router (actually it's a modem-router, Actiontec for FIOS) that's type 1, and of course you could make your own type 1 if you can write your own firmware. I've only worked with the older DD-WRT's and they only support type 2 hostnames but can't see why they wouldn't add type 1 support - except that it would require local storage...

I'd rather type 2 anyway...

[eccerr0r]

Re: New Router, Small Problem

BTW, DNSMASQ, which is used on GPL firmware http://www.thekelleys.org.uk/dnsmasq/doc.html supports "Type 1" so I suspect later versions of DD-WRT support this. The "importing names from the DHCP subsystem" is the feature that's wanted though how you configure this through the GUI is implementation specific...

And yes this runs on your router. So if you can't hack your router, no point in proceeding further with this...

[retiredcaps]

Re: New Router, Small Problem

Old router was Asus RT-N56u Before that was a Cisco E4200v2 (can't use dd-wrt on it)

A quick search shows that both the above routers can run openwrt and possibly lede. openwrt -> lede, but now rumors they are going to merge back again later this year.

I normally go retrieve "old" routers if the person discarding is within 10 minutes of me and load openwrt/lede. I use them at home and give them away to friends and family to replace their old outdated router software.

[eccerr0r]

Re: New Router, Small Problem

Has Tenda router support gotten better? Last I heard it was very spotty.