Connected to Nework but no Proxy Authentication

Hello! I would like to share some experience of other people in their Network. If you are the network administrator, I think this must be implemented:

1. Network and Security Policy

2. Network Auditing every month

3. Checking of Policy every quarter

4. Network Report every quarter

5. Content Filtering and Proxy for users (optional). This helps me a lot.

Note: Of you guys out there can add more. It would be great!

The problem starts here!!!

Setup: Linux (Gateway), IP Tables (Firewall), Squid (Proxy), Dansguardian (Content Filtering) and a DHCP.

Senario: Your client/users opened his/her web browser but no Proxy Authentication POPup (client browser is configured to use proxy server). The client/user restart the browser but nothing happened. He/She tried to restart the computer but nothing happened =D. Other System Administrator tried to check if the proxy server is running correctly in the server and double check the firewall. But proxy server and firewall are running correctly, what do you think is the problem?

Gateway IP Address: 192.168.3.250

Netmask: 255.255.255.0

DNS: 192.168.3.250

Here are some basic steps to troubleshoot this problem:

1. Make sure proxy is running correctly.

2. Make sure proxy authentication is enabled in the server.

3. Try to reconnect your LAN Cable or try to release and renew IP Address:

For Windows: ipconfig /release
ipconfig /renew

For Linux: /etc/init.d/network restart
/etc/rc.d/networkmanager restart
/etc/init.d/networking restart

4. Double check network settings of Windows
For Windows:ipcofig /all
IP Address: 192.168.3.125
Netmask: 255.255.255.0
Gateway: 192.168.3.250
DNS Server: 192.168.1.1 (Make sure DNS Server is Correct)

For Linux: ifconfig

wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 metric 1
inet 192.168.3.125 netmask 255.255.255.0 broadcast 192.168.3.255
inet6 fe80::21c:bfff:feac:c3f3 prefixlen 64 scopeid 0x20<link>
ether 00:1c:bf:ac:c3:f3 txqueuelen 1000 (Ethernet)
RX packets 890738 bytes 1035419263 (987.4 MiB)
RX errors 0 dropped 18 overruns 0 frame 0
TX packets 948781 bytes 139179037 (132.7 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

Check the gateway route -n 

0.0.0.0           192.168.69.50      0.0.0.0               UG      0      0      0      wlan0
192.168.69.    0 0.0.0.0              255.255.255.0   U         0      0      0      wlan0

Check the DNS cat /etc/resolv.conf

# Generated by NetworkManager
domain sample.com
search sample.com
nameserver 192.168.1.1

5. Tracert

tracert 8.8.8.8

Tracing route to 8.8.8.8 in-addr.arpa [8.8.8.8]
over a maximum of 30 hops:

1	<1ms	<1ms	<1ms	1.1.168.192.in-addr.arpa [192.168.1.1]
2	1.1.168.192.in-addr.arpa [192.168.1.1] reports: Destination host unreachable.

Trace Complete
6. Check Windows Event Logs
" Event Logs from windows indicated that the IP Address lease 192.168.3.64 for the Network
with network address 0xB8A386077582 has been denied by the DHCP Server 192.168.1.1
(The DHCP Server sent a DHCPNACK message)."
7. Windows Lan Manager has !(exclamation point), indication that their are conflict gateway or DNS in Network.

Conclusion: Therefore their are other gateway(router) installed in your network. This gateway broadcast DNS on other workstation. Think what are the events happened before the problem (this is helpful when it comes to troubleshooting). Trace the other gateway(router) and turn it off.

Advertisements
Categories: linux, Linux OS, technical | Tags: , | Leave a comment

Post navigation

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Create a free website or blog at WordPress.com.

Dale Carnegie Training for Asia Pacific Region

blog site for Dale Carnegie in the Asia Pacific Region

inspirationenergy

be inspired to greatness

How Leaders Manage

Shape your Character change your life.

Let's Reach Success

Habits, purpose and a little bit of zen.

adoptingjames

Read our Mission. Find out how you can help us adopt James.

juliansherman.net/

Building A Business While Having A Life

Capo - The Event Planners

We do the work, You get the honor!

mookology.

book + movie = mook. this is mookology.

Book of words

Books, reviews and all things worth reading

What an Amazing World!

Seeing, feeling and exploring places and cultures of the world

Tech

News and reviews from the world of gadgets, gear, apps and the web

Bonsai Tonight

An educational website about the styling, care and display of bonsai.

you and mie

let's make things

bhelai

Just another WordPress.com site

Piano Transcriptions

Piano sheet music blog you can comment on

8layertech

Your fresh contents delivered by 8layertechnologies

THE SWOOSH RUNNER

Making Every Step Count

%d bloggers like this: