ROUTER on a STICK

[bicesz19780518]

Hello community!

Maybe someone can help me with this problem!

I have set up a router on a stick config, 2 laptops 2 2950T switches, and of course a Router!

Problem! pc1 can ping his gateway, pc2 gateway, and pc2

BUT pc2 can ping his gateway, pc1 gateway, but her comes the funny part CAN PING PC1 JUST SOMETIMES!

HAS someone faced a scenario like this!

I hope so!

Hoping for "an" and "any" explanation!

I.Z

[John Blakley]

Are you trunking the port that the router connects to? You'll need to have the vlans configured on the switch that are on the router. Can you post the config?

[fb_webuser]

Can you publish a picture? I don't understand what for do you have to switches?

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Posted by WebUser Aleksandr Yanovskiy

[bicesz19780518]

thx for your quick response, so here you go

i made a model in Pt, but it is real hardware i am using!

i was thing that maybe the pc1 or pc2 is blocking icmp replay, but was turning everting on, under firewall ICMP options, and the firewall on both PC's off!

I USE THE 2 SWITCHES TO PRATICE SKILL!

I AM TRUNKING THE PORT THE ROUTER CONNECTS TO, COS

[milan.kulik]

Hi,

the router config looks OK.

It's not visible though if the switches are configured correctly:

a) is the switch port to which the router is connected to configured as trunk, no negotiate?

b) are the PC ports assigned to correct VLANs?

c) if you connect the PCs to the same switch, is the problem still presisting?

d) if you swap the PCs, is the problem "moved"?

HTH,

Milan

[fb_webuser]

Post all configs of all 2 switches and router. Because it's not all clear for me

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Posted by WebUser Aleksandr Yanovskiy

[glen.grant]

  Keep in mind also packet tracer has been known to be buggy so there may be nothing wrong with the config. 

[bicesz19780518]

Connected the PC1 and PC2 to the same switch SW1 and problem still persists!

I changed even the router,

!!!!! seems like I can ping from PC2 to PC1 till the point I am issuing a ping command from PC1, after that it take some time aprx. 5-6 min until i have a successful ping from PC2

I have made all the changes, recommended, noneogitiate on trunk port to Router on sw1, swap the pc, and problem still persists!!!!

FEARS OF INSOMANIA :)))) – HELP

HERE ARE THE CONFIGS!

SW2

[cadet alain]

Hi,

can you post shcd nei on all devices, sh int trunk on both switches, sh int x/x switchport on both switches for the access ports, sh ip route and sh ip int br on the router and sh arp on the router.

When the ping is unsuccessful ( do a ping -t)  look at the arp cache on both PCs with arp -a and post output as well as

the CAM table of both switches for the MAC of both PCs( sh mac dynamic xxxx.xxxx.xxxx  where you replace with the MAC addresses obtained with ipconfig /all).

Regards.

Alain

[bicesz19780518]

NO IP ROUET CHACHE - THIS IS SUSPICIOUS

[cadet alain · Accepted solution]

Hi,

you don't care about it as you are not routing with the switches but only L2 forwarding.

Regards.

Alain

[bicesz19780518]

AND SORRY THE TOPOLOGY

[bicesz19780518]

dear allen!

i think this is geting very close, the arp chache of PC2 was empty! thus PC1 has his dg in his arp chach!HMMM

I'll come back to this tomorrow, and thanks to all for support!

I.Z

[bicesz19780518]

DEAR ALL!

It cam out, that something is not right with pc2, because i changed PC2 with another pc, and makeing succeful ping all around the network!

SO THANKS EVERYBODY FOR YOU SUPPORT AGAIN!

I CLOSE THE DISCUSSION, AND WILL TROUGH AWAY THIS PC!!!!!!