Networking issue

[sultancisco1824]

Dear Sir,

Please be  informed that am going to explain the issue which am facing my small organisation.

I am working independently in small company and we have a Network infrastructure in our domain. Since long back its working good, but recently 3-4 days am facing a network connectivity problems in my users. The internet connection is not connecting to all users and sometimes it connecting it means not stable. I called my ISP provider to check the DNS and internet connection, he tested and checked. From his side Gateway of router is pinging. After he said that to connect the laptop direct to router (We have Cisco 800 series Model : 881 with professional service) and check the pinging test with router gateway. So the coordination with ISP provider its confirmed that the internet connection is working good and he said check your LAN Connections in Switches.

Finally i find the problem is coming from networking it means in Switches. Then i check the all connections which is connected to switches, at time i remove the cable of specific user and reconnect it works. And if he Logoff or shutdown their PCs and Logon it again it disconnect same.this is coming to all users and at the i restart the switch from power cord and start again then it all working. If any one shut down his PC at the living time and again he came and turn on his PC he cannot be able to connect the internet. So again we need to restart the switch.

So, this is issue which am facing more. For your understand find the below requirements and components which we are using:

Switches : Cisco SB Switch, SG 300-28Port Gigabit PoE Managed 

Router : Cisco 800 series Model : 881

Note : we have Server 2012 R2 in that they is no issue because its directly connected to router port.

Behalf of this switch is connected to router with that switch-1 another same switch-2 is interconnected.

Behalf of this one of the Avaya PBX is connected to switch-1, So this is all our infrastructure.

I hope you can understand the scenario . So please requesting you to reply to this post.

am helpless plz plz urgent...

Kindly find the attachements

TCP/IP(LAN) setting: Server

Ip: 192.168.2.3

subnet: 255.255.255.0

Default gateway: 192.168.2.1

DNS: 37.99.140.1

Alternate DNS: 94.77.249.126

Router : 37.99.129.165

Router Gateway: 37.99.129.166

Regards,

Shaik

+966548212983

[Aaron Harrison]

Hi Shalik

At the time when your PCs have problems, is your Windows 2012 server OK?

Aaron

[sultancisco1824]

Hi Sir,

Yes its working fine that time.

But the problem only in PCs which is connected to switches.

Looking forward to hearing from you.

Regards,

Shaik

[walter baziuk]

Pls post a diagram with ip addres

can you alo post your config files

without these, it's hard to help

[Praveen Vincent Vas]

I agree with Mr Walter. Please post configuration commands as well as diagram

[Praveen Vincent Vas]

Dear Shaik

  With reference to your problem I can tell you that the ICMP Destination net unreachable message is one which a user would usually get from the gateway when it doesn't know how to get to a particular network. So I suggest you to check the routing part and also check with proper configuration of static and default route to the internet. As problem is faced by all the users this may not be a issue with any individual computer I believe. And also verify that there is no loop happening in the network. Good Luck.

Praveen

[sultancisco1824]

Dear Sir,

Firstly thank you for response.

I checked the routing path and static IP settings its fine. Its problem for all users but randomly sometime 2, 3 users.

one thing i want to say the loop is available in network, Loop means a joint connector right? some connection are jointed with connectors and after that going to switches. So, on the behalf of this i want to ask you my server is directly connected to cisco router, with this is their is any problem for DNS.?

Server TCP/IP Settings:

192.168.2.3

225.255.255.0

129.168.2.1

37.99.140.1

94.77.249.126

According to the below attachment. At the time of disconnection issue when i ping the gateway of router 37.99.129.165, its not pinging it giving reply from server gateway 192.168.2.1 Destination net unreachable. Why please ? Again some cables connections are connected with joint connectors.

Hope you are understand my explanation.

please am helpless on this issue to find, am very thankful for your cooperation.

Regards,

Shaik

+966548212983