ZyNOS FAQ
ZyNOS is ZyXEL device's proprietary Network Operating
System. It is the platform on all ZyXEL device routers that delivers network
services and applications. It is designed in a modular fashion so it is easy
for developers to add new features. New ZyNOS software upgrades can be easily
downloaded from our FTP sites as they become available.
2. What
is the default console port baud rate? Moreover, can I change it?
To access the ZyXEL device via console port, a computer equipped with communication software such as HyperTerminal must be configured with the following parameters.
The default console port baud rate is 9600bps,
you can change it to 115200bps to speed up the access.
3. How do I upload ROMFILE via
console port?
In some situations, you may need to upload the ROMFILE,
such as losing the system password, or the need
of resetting system to factory default.
The procedure for uploading ROMFILE via the console port is as follows.
4. How do I upload the ZyNOS firmware code via console port?
The procedure for uploading ZyXEL device via console is as follows.
5. How do I upgrade/backup the ZyNOS firmware by using TFTP client program via LAN?
The ZyXEL device allows you to transfer the firmware from/to ZyXEL device by using TFTP program via LAN. The procedure for uploading ZyNOS via TFTP is as follows.
6. How do I
backup/restore configurations by using TFTP client program via LAN?
7. Why can't I make Telnet to ZyXEL device from WAN?
There are three reasons that Telnet from WAN is blocked.
Source IP= Telnet host
Destination IP= P-334WH's WAN IP
Service= TCP/23
Action=Forward
8. What should I do if I forget the system password?
In case you forget the system password, you need to upload
ROMFILE to reset the system to factory default.
After uploading ROMFILE, the default system password is '1234'.
9. What is SUA?
When should I use SUA?
SUA (Single User Account) is a unique feature supported by ZyXEL router which allows multiple people to access Internet concurrently for the cost of a single user account.
When ZyXEL device acting as SUA receives a packet from a
local client destined for the outside Internet, it replaces the source
address in the IP packet header with
10. What is
the difference between NAT and SUA?
NAT is a generic name defined in RFC 1631 'The IP Network
Address Translator (NAT)'.
SUA (Internet Single User Account) is ZyXEL device's implementation and trade
name for functioning PAT which is a specific type of NAT. SUA( or PAT for NAT)
translates address into port mapping.
The primary motivation for RFC 1631 is that there is not enough IP address to go around. In addition, many corporations simply did not bother to obtain legal (globally unique) IP addresses for their networks and now finding themselves unable to connect to the Internet.
Basically, NAT is a process of translating one address to another. A NAT implementation can be as simple as substituting an IP address with another. This allows a network to rectify the illegal address problem mentioned above without going through each and every host.
The design goal of ZyXEL device's SUA is to minimize the
Internet access cost in a small office environment by using a single IP address
to represent the multiple hosts inside. It does more than IP address
translation, so that multiple hosts on the LAN can access the Internet at the
same time.
11. How many
network users can the SUA/NAT support?
The ZyXEL device does not limit the number of the users but
the number of the sessions. The ZyXEL device 334 supports 2048 sessions that
you can use the 'ip nat
iface enif1' command in menu 24.8 to view the
current active sessions.
12. What are
Device filters and Protocol filters?
In ZyNOS, the filters have been separated into two
groups. One group is called 'device filter group', and the other is
called 'protocol filter group'. Generic filters belong to the 'device
filter group', TCP/IP and IPX filters belong to the 'protocol filter group'.
13. Why
can't I configure device filters or protocol filters?
In ZyNOS, you can not mix different filter groups in the
same filter set.
14. How can I
protect against IP spoofing attacks?
The P-334WH's firewall will automatically detect the IP spoofing and drop it if the firewall is turned on. If the firewall is not turned on we can configure a filter set to block the IP spoofing attacks. The basic scheme is as follows:
For the input data filter:
Filter rule setup:
Where a.b.c.d is an IP address on your local network and w.x.y.z is your netmask:
For the output data filters:
Filter rule setup:
Where a.b.c.d is an IP address on your local network and w.x.y.z is your netmask.
All contents copyright (c) 2006 ZyXEL Communications Corporation.