I need a ZyXEL ADSL router guru to have a look at this please.

I am in need of some simple assistance and I'm hope someone can help.

Can someone please tell me if this is the way to allow `ANY` LAN host
to access the router administration menus by TELNET, but at the same
time allow `ONLY` one IP from the WAN link to access the same
administration menus? This is without having to fiddle with the
remote administration access menu every time one or the other access
options are required. Something that can be set once and left alone.

This is for a ZyXEL Prestege router.
Name: P650R-31
Routing: IP
ZyNOS F/W Version: V3.40(GT.3) | 9/9/2003
ADSL Chipset Vendor: Alcatel, Version 3.9.122
Standard: Multi-Mode

In the example `ANY` IP on the LAN should have TELNET access to the
router's administration page AND `ONLY` IP 81.1.2.3 has access to the
same TELNET administration facility from the WAN (aka. Internet).

Is this correct?

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Menu 21.6.1 - TCP/IP Filter Rule

Filter #: 6,1
Filter Type= TCP/IP Filter Rule
Active= Yes
IP Protocol= 6, IP Source Route= No
Destination: IP Addr= 0.0.0.0
IP Mask= 0.0.0.0
Port #= 24
Port # Comp= Equal
Source: IP Addr= 81.1.2.3
IP Mask= 255.255.255.255
Port #=
Port # Comp= None
TCP Estab= No
More= No, Log= None
Action Matched= Forward
Action Not Matched= Check Next Rule

Menu 21.6.2 - TCP/IP Filter Rule

Filter #: 6,2
Filter Type= TCP/IP Filter Rule
Active= Yes
IP Protocol= 6, IP Source Route= No
Destination: IP Addr= 0.0.0.0
IP Mask= 0.0.0.0
Port #= 24
Port # Comp= Equal
Source: IP Addr= 0.0.0.0
IP Mask= 0.0.0.0
Port #=
Port # Comp= None
TCP Estab= No
More= No, Log= None
Action Matched= Drop
Action Not Matched= Check Next Rule

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Menu 11.5 - Remote Node Filter

Input Filter Sets:
protocol filters= 6, 12, 11
device filters=
Output Filter Sets:
protocol filters= 1
device filters=
Call Filter Sets:
protocol filters=
device filters=

(Entry for rule `6` is the one that's been added above.)

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Menu 24.11 - Remote Management Control

TELNET Server:
Server Port = 24, Server Access = ALL
Secured Client IP = 0.0.0.0

FTP Server:
Server Port = 21, Server Access = LAN only
Secured Client IP = 0.0.0.0

Web Server:
Server Port = 80, Server Access = LAN only
Secured Client IP = 0.0.0.0