TP-Link router (specifically TD-W9980) LAN configuration options - what do they do?

[Chris Green]

I have a new (to me) TP-Link TD-W9980 VDSL/ADSL Wireless router. I
have now got the basics configured as I want (FTTC connection, wired
LAN, etc.) but I'm still rather puzzled by some of the configuration
options, specifically the LAN ones.

The User Guide is useless, it just tells you exactly what the
configuration GUI shows you anyway. It doesn't tell you what the
configuration options do for you.

The things that particularly puzzle me are:-

1 - In 'LAN Settings' you can 'Enable Second IP', this allows you to
enter a second IP address and mask, but there's no clue as to what it
actually does. Does it simply allow all the ethernet (and WiFi?) LAN
ports of the router to talk to a different subnet? If so then how
well isolated are systems on the two subnets? It doesn't seem to set
up a DHCP server on the second subnet range.

2 - In the Network section there is also an option 'Interface
Grouping', you can assign LAN, WAN and WiFi to different groups but
again there's no clue as to *why* this might be useful. Are the
groups (even though on the same subnet) isolated from each other, or
what?


If anyone can elucidate at all I'd be very grateful. :-)

--
Chris Green
·

[PeeGee]

Re: Qn2 - the clue is the enable VLAN feature tick box. A VLAN allows
traffic only between ports in the group and, usually, a port can be in
more than one group. Devices on the "common port" can communicate with
device in both groups. It can be really useful on 24 port switches.

It may even be possible to control traffic using your two WANs - though
I haven't thought any further about that.

--
PeeGee

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[PeeGee]

Re: Qn1 - It is a single IP address providing access to the management
interface, according to the manual. It appears this can be totally
independent of the "normal network" as the router will respond to any
appropriate traffic passing through the "switch". It should then be
possible to disable management access via the "normal network" through
system tool -> manage control.

[Chris Green]

Ah, so it's a silly new name for VLANs, thank you - and it might very
well be useful to isolate guest WiFi users to some extent for example.

> It may even be possible to control traffic using your two WANs - though
> I haven't thought any further about that.
>

I've yet to work out how (or even if it's possible) to have two WANs
on the TD-W9980. It certainly doesn't seem possible to have an
ethernet WAN as well as an ADSL/VDSL one.

--
Chris Green
·

[Chris Green]

PeeGee <trie...@yahoo.co.uk> wrote:
> >> The things that particularly puzzle me are:-
> >>
> >> 1 - In 'LAN Settings' you can 'Enable Second IP', this allows you to
> >> enter a second IP address and mask, but there's no clue as to what it
> >> actually does. Does it simply allow all the ethernet (and WiFi?) LAN
> >> ports of the router to talk to a different subnet? If so then how
> >> well isolated are systems on the two subnets? It doesn't seem to set
> >> up a DHCP server on the second subnet range.
> >>
>

> Re: Qn1 - It is a single IP address providing access to the management
> interface, according to the manual. It appears this can be totally
> independent of the "normal network" as the router will respond to any
> appropriate traffic passing through the "switch". It should then be
> possible to disable management access via the "normal network" through
> system tool -> manage control.
>

But what it says is:-

Enable Second IP: You can configure the modem router’s second IP Address and Subnet
Mask for LAN Interface through which you can also access to the Web-based management
page as the default IP Address and Subnet Mask.

Does this really actually mean what you said? :-) I guess it has
lost something in translation or the manual writer's less than perfect
command of English.

--
Chris Green
·

[Chris Green]

Hmm, maybe it *should* be as you describe but it isn't! :-)

I tried adding a group and put LAN1 and WiFi into it. The new 'group'
gets assigned a different IP from the default group and you can't put
any interface into both groups.

So essentially it's simply separate subnets and you can assign LANs
and WiFi interfaces to them, but (unless you add some custom routing)
it doesn't appear to be possible to have communication between them
and interfaces can't be in more than one group.

It's quite unlike the VLANs on my Draytek Vigor 2820n, on that the
subnets stay the same but (if I understand it right) you can't 'see'
from VLAN to VLAN.

--
Chris Green
·

[Michael Chare]

I rather think my Speedtouch routers have always had multiple local IP
addresses. Can't say I have found much use for the 2nd address.

--
Michael Chare

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