This is one of multiple LAN local area network troubleshooting videos.
In this example users are complaining that PC one can't ping the PC to his Rodda one acting as PC one
paying $10 one the sweet or two.
Looks like that pings or failing.
So we don't have connectivity from PC one PC to show IP ront default gateway of the PC is configured
to 10 to 1 2 2 2 2 5 4.
This is a subscriber is Virata But IP routing has been disabled hence the writing table looks as follows.
IP writing is disabled but a default gateway has been configured.
Hence we see default gateway as follows.
Can we ping the default gateway.
Yes we can can be paying villans 3 on the Default Gateway PC 2 is in violent 3.
And notice here is the default gateway so which one.
Some of the documentation and this topology hasn't been updated.
And that's something you constantly going to find when troubleshooting real networks.
So we can ping villans 3 on the default gateway.
Can the default gateway ping router to see just switch one acting as the default gateway Kennet paying
10.0 one two or three to two.
No it can't.
So it looks like we have a problem between switch one and this router.
Let's check if we have connectivity between the access switch and the core switch.
My typologies not showing the IP address of the access switch.
So let's jump onto the access switch and confirm and check what it's IP addresses.
This is a problem you may encounter if you don't have no IP domain lookup enabled these devices are
always very layer 2 switches and routers ingenius 3 no IP domain lookup is not enabled by default on
these devices.
So that's probably something we want to do immediately to save us.
Frustration.
So the command is no IP domain look up say show IP interface brief which has this IP address from Villon
one can we paying the cost switch on villaine one looks like we can't.
Can we ping the score switch.
Switch to.
So before going any further let's update the documentation.
That's the IP address of the switch.
Let's check if the switch can paying switch to switch to show on the interface.
Brief OK it has IP addresses on the three villans.
So what I'll do is update the diagram.
It's 2 5 3 in all the violence that's IP addresses off switch to can switch for the access switch paying
$10.
1 1 2 5 3.
Doesn't look like it can.
So it looks like there's a problem on the link between switch to and switch for show CTP neighbor.
We do see a neighbor relationship between the local switch and router 2 as well as switch to shows on
the interface.
Brief interfaces look up show interface trunk.
It looks like interfaces trunking to the core.
Let's check the configuration on the cost which so show interface trunk can you see the problem.
What I'll do is move the console to the left chair can you see the issue.
What's the problem between switch to and switch full.
OK so on switch for gigabit to 0 0 has trunking on being kept solution is a two to one.
Q native villain is one on gigabit zero one on switch to trunking is on.
But the encapsulation is Eisele so trunking is enabled with a native villain of one but the encapsulation
is wrong or different.
So encapsulation is Eisele on this port where as on the port and cancellation is dot one.
Q You need to have the same encapsulation of both sides.
So what I'll do is change the encapsulation show run interface gigabits for one that looks better.
Kand the switch now paying switch for with IP address 10 1 1 4 it still hasn't come up.
What we may have to do is wait a bit but what I'll do just to force things is shut the interface down
and then no shut it.
You may have a slightly different experience engine history versus a physical switch.
We still only see switch one through CTP that may take a while to come up.
Faces up up show interface trunk trunking is now set to edit to the one cume both sites.
Can this switch now paying switch to use it can.
So that looks better.
If you have issues you may want to shut and then shut the interface so that the encapsulation and other
options are renegotiated.
Second PC one ping PC to check if that works.
OK we still have a problem.
PC one on the left is not able to ping PC to let's do a trace to 10 1 3 2 so it gets to the default
gateway and then the trace times out can PC to Rodda to acting as PC to ping its default gateway
Yes it can
noticed suddenly here we had some kind of put
and I was actually running an ICMP debug here and noticed the output.
So let's try to do that ping again.
And what I'll do is enable a debug MP
So the pings are suddenly working and that may be a genius 3.
The problem here is notice this option.
Be careful especially with PCs you may have a problem where everything looks good but the PCs can't
ping each other.
What I should have configured is an IP default gateway of 10 to 1 or 3 or 5 for.
So in a real environment that ping may not work.
It depends where the proxy arp is enabled on your will.
In TV land routing devices proxy up will allow a device to proxy the default gateways of other devices.
In many cases that's disabled so you need to have the default gateways enabled on both sides.
The IP route notice default gateway show IP Raat default gateway is configured so be careful in a real
environment and in the exam that the default Gateway's on both age devices are configured properly.
So we've not fixed the apology.
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