Troubleshooting Basic Routing - Video By Sikandar Shaik || Dual CCIE (RS/SP) # 35012

[Music] in this video we're going to see some of the basic troubleshooting which is rating the dropping so we'll start with how to troubleshoot your routing process here so whatever the type of routing we are using so here I'm not specifically discussing any type of routing here so the routing means it can be your static routing or it can be your default routing it can be our IP EIGRP or it can be able to spear flopping so any type of routing there are some few basic things we need to keep in mind when we verify our routing configuration so anyway we'll get into some individuals routing process like our IP couple shooting EHR POF troubleshooting in our separate videos here I'm just discussing some of the basic routing process so the first thing always you need to understand the basic routing process so you should have a very good understanding on how the routing process happens like if you remember in my basic videos basic routing videos I already have a separate video discussed over their effort explaining how the routing process happens I'm not getting into that again but just quickly I will explain you that if this device connecting on the lan want to communicate with another device in a separate line the first thing it should it should be defined as a gateway so the packet goes to router and the router is going to check the routing table verify the next hop if the next hop address is correct and then it will forward the packet to router 2 and the router 2 is going to take the routing table and then forward the packet to the layering of this so we already verified in detail how the routing process happens so you should have a very good understanding of that ordering process and then verifying your routing table we're using show IP route command and finally if there is a miss configuration of any routing considerations you should verify it by using a show running configurations and finally we need to do any changes required as per our requirement so let's get started here so I'm going to use one simple scenario here where we are going to take some fire out of multiple routers and we'll take some simple example and we'll try to understand how the routing process happens here so this second example there is a device with 192 168 1.1 connecting on the router one lamp is not able to access one I to 168 5.1 which is on the router file and so now when when these two devices are not communicating so there can be the problem can be anywhere now the first thing of troubleshooting is to figure out where the problem is okay that is something because you know we cannot really get into each and every device and verify the configurations the problem might be in your gateway it might be the connecting between the router 1 & 0 2 or it can be on the router 1 configurations or it can be router two configurations it can be router 3 router 4 out of 5 or it can be the problem with the connectivity or it might be a problem with a device in the land so now tracing the problem with exactly it is is the main task of troubleshooting so now how to do that so the first thing always make sure that whenever you are starting troubleshooting first step I really recommend to make sure that divide your network into two parts probably maybe two parts I can say so here I am dividing my network into two multiple parts like first make sure that from rach23 you are able to access this user or not so in case if you are able to access from router 3 you are able to access this user in that case there is no problem on the right side so which means we really no need to check much on the right side because mostly if router 3 is able to access the 5.1 user which means all you are routing from router 3 to 4 4 to 5 & 5 to land is perfect so in case if they are not able to access then you can start troubleshooting on this side so maybe this side is perfect or maybe the problem on both the sides so we need to check out and assuming that this part is perfect from the outer 3 2 out of 4 everything is working fine so there is no problem here so now you can try trying to access from router to if router 2 is also able to access then there is no problem from router 2 to dot o file so most likely the problem might be in your connect tightening connectivity between router 1 to router 2 or it might be in your land resources so the first thing tracing the problem where exactly in between which two routers it can be between outer one and two or two and three or three and four and five and five is the main thing so let's take an example router 3 is able to access from router 3 I am able to access the fight or network but from router - I am NOT able to access that so which means there may be problem on the router 2 configurations routing conversations or there might be a problem on the LAN interface which is cutting between or it can be problem on any other any other things so we need to figure out that and then we need to figure out what are the possible reasons further for this may be the miss considerations find out and fixity okay so that's the first thing we need to do so router 2 assuming that router 12 out of three is having the problem so now whenever you realize that there is a problem we did not go to we're down to three router three is able to access 5.1 but from router - I am NOT able to access to that network which means the problem is are out of the state the first thing I will suggest you to check the connectivity between router 2 and outer 3 because sometimes what happens we have a very basic problems like connectivity issues and we spend unnecessarily troubleshooting your routing configuration so routing configurations anyway we need to verify but it has to be done only after connectivity which i really suggest you so make sure that your physical connections are up the link connecting between down to 20 which over the two devices you will has a problem and then we need to get into a routing configurations where I am going to verify my routing table and make sure that whatever the destination network that day station encode is in my routing table or not so you've got entries present in your routing table and make sure that in your routing table entry is present with a valid next hop sometimes what happens you have an integer routing table but the next hop you is wrong or it might be misconfigurations which can really affect your routing routing communication the communication exchange the addiction between these two routers so i really suggest you to check the routing configurations you can using static or default routing maybe you're giving a wrong next table if you're using any other protocols then OSPF EHR related troubleshooting we have discussed much more in detail so it varies depending upon the type of the routing but the major thing is you have to make sure that the route is present in the routing table if there is no route in the routing table there is no point in communication so you have to make sure that your route must be present in the routing table so once you make router 2 is able to access so maybe the connectivity issue here so once we fix it the next thing we need to do is we need to make sure that router 2 should be able to access your fight or network and then finally from router 1 you should be able to access and then finally you should be able to access so you have to make sure that that outer one must be able to access so finally make sure that your gateway if some router 1 I can see the routing table entry but from the LAN I am NOT able to access make sure that you have a connectivity between your LAN uses a decade wave so these are some of the things which we need to keep in mind when we do troubleshooting so i really suggest you to check out these things but depending upon the type of the protocols or type of the routing we're using the steps will vary but the overall troubleshooting your routing concepts this is how we can minimize the number of configuration verifications and also we can minimize by going to each and every router and verifying it I got a simple scenario here I got the same three routers where I am using 192 168 1 dot 100 in my outer one LAN 1 I to 168 2001 I to 168 3 dot 100 here I already inserted some of the issues in my routers here manually I wait some errors and what I want I'm going to do is I'm going to verify make sure that my PC 1.1 must be able to access 3.1 user so that is what my requirement so I need to make sure that my 1.1 user somewhere here is trying to access your 1.3 users somewhere on the third line but as per my requirement they are not able to communicate that is my what exactly is happening they are not able to communicate I want to make sure that these two devices must be able to communicate so the problem can be anywhere so I'm going to I'm going with my step by step process to figure out and verify where the problem is so start with my router 1 the first thing what I'll do is router 1 if you if you really insure so now depending upon your requirement you can check by pinging to the Gateway and making sure that finding out the problem only this particular user is facing the problem or all the users are facing a problem sometimes what happens only this user is not able to access this network whereas the remaining users still I can access this so if you come if you realize something like this then the problem is not with your routing configuration the problem is not with your gateway and the problem is not with your switch the problem might be with your local device so these are some of the basic testings again we need to do before we we directly jumped over auditing configuration so every time there won't be a routing problem so but here we focus on routing majorly but every time it might may not be a routing problem if all the users in the LAN are not able to access the destination that is 192 168 3.1 in that case I can really ensure that there might be a problem with my centralized device which or it might be a problem with my router for routing wall variations so in my case as we are doing double shooting so there is no problem here I verified it so the route bit not only this PC all the users are not able to access so if you want to can try and check I am going to my PC where I have an IP address I'm going to verify by pinging to my gateway first making sure that you should be able to access here so you can see from my 1.1 PC I'm not able to access my gateway which means there is some problem between this part ok so let me try to check the second PC which is my 192 168 1 dot 2 1 & 2 1 6 a 1 not 100 it is for a transition one dot 100 so you can see I am not able to ping to 100 from the 2nd PC also most likely the problem is not the connectivity between these devices it might be the problem here so what I will do is I will try to go and verify my router configurations so as for my interface which is correcting F 0 by 0 on this side it 0 by 0 much main idea so maybe by mistake I Remes so this is the problem here you can see the 0 by 0 interface which I am connecting to my land is not having any IP errors so maybe due to some miss configuration sometimes type II errors might be removed so I am going to make sure that the IP address is correct to 5 / - 5 / - / 0 as no on command and now if I verify my device it is having the IP address 192 168 1 dot 100 now I'll try to ping to my land users that is one I - 1 6 a 1.1 PC you can see I am getting a replies similar way I should be able to ping the 1.2 also similar way 1.3 but not for so make sure that your LAN users are able to access your gateway so because that is the first thing in you check connectivity part make sure that there is no problem in the connect see between the land and then once we verify this you are able to access a gateway the second thing we need to verify in your PC that device sometimes miss configuration of IP address sometimes the Gateway address may not be given or the gate vectors might be wrong given so that is something we also need to verify make sure that the device which are not able to access they have a proper gateway configured so was verify this part we can confirm that this particular land part is perfect so but the packet is going to router if I try to access my other network resources that is one into 168 3.1 which is which is somewhere on the router seal and you can see the packet is going till router 2 that is 10.00 2 but after that it is not going which means now as per our scenario here the packets from starting from 1.1 is going to the outer 1 and outer one is sending the packet or Auto - and offer that it is dropping the packet here which means it's not going after that so most likely the problem is here because on the router the one the routing concentrations are perfect that is the reason the packet is still going till router 2 so we need to check the router 1 configuration if you want you can check I can check but as per my output I can easily say that the packet is going to the router - if you want to verify if any packet comforted or network it should be sent to 10.00 - you can see you any packet come for through our network it should be sent to 10.00 - which means this consideration is correct this is also correct so all the conversations are correct here so the problem might be on the router - routing configurations or maybe something miss configure the packet is not going out and after - so let us go to the outdoor - and verify our mounting configurations so I am on my router - here on the router - I am going to say YP route command and you can see there is no entry for 192 168 3 thought Network because you know if you remember the routing process here by default the packet goes to the outer one outer one sense router to router - it takes the routing table for 192 168 3 dot Network and if there is no entry for the routing table it is going to simply drop the packet that is what happening here on the router to router to do not have entry for 192 168 3 dot Network so if I were verified so maybe you can confirm that maybe you can think I did the configurations you really know you did that but it's not coming in my routing table means sometimes what happens you write a route and if you write a wrong next top you can see here in my example the next hop address is 11.00 - but it is written as 15.00 - so long next top address also can affect your things so here's the next hop address is wrong so what I can do is I can remove that configuration always add no before that and then I am going to say IP route 1 9 - 1 68 3 . network - fire fire 255.255.0.0 leaven or 0 0 - so now if a very family outing table after adding a proper entry still I am NOT getting the route and if you try to see here there is one more thing to watch here router 2 is having how many country interfaces this is my tiny interface which is on a 0 by 0 11 . network is on a 0 a 1 and a 0 by 0 that is these three interfaces I got three interfaces which are connecting to my network but here you can see there are only 2 C's so I can see a 0 by 0 I can see a 0 by 0 but I cannot see a 0 by 1 the free surface is not listed whenever you see those interface is not listed in the routing table you can you always need to check this interface is in downstate it can be a little down or it can be down down or it can be up and down whatever the reason so we did the troubleshooting the connectivity already so I'm not getting into that part whenever you see your pre-cut interfaces or not relation your routing table you need to understand that your interface is done you can see it as 0 1 interface is in downstate now if I verify what is the reason for that show IP interface brief if you want to verify if you see down down there are most likely the reasons might be the remote device powered off maybe the remote device powered off here or it can be this port is in shutdown state let me check on the router 3 so I'm going to check on the router 3 show IP interface brief you can see I'm connecting a 0 by 0 and it is at Main Street to the town so this is the reason for it so I am going to s 0 by 0 and then I'm going to be no shutdown command ok so already I did this troubleshooting in my separate videos I am NOT getting into this connectivity troubleshooting here so now you can see the route is link is up and if I go to my router to again show IP route now I can see the route and see my routing table as well as with the correct next top models so once we fix it let us go to my router of PC one and the last time when I was trying to ping to 3.1 I was not able to ping now I am going to try again now I should see the reply should come if it is not coming then I have something more to troubleshoot so you can see I am able to communicate between 3.1 if you tried trace command say search you can see how the packet travels even sometimes if you see the entry in the routing table but if you are not able to ping then tracers will really help you useful command very useful command sometimes what happens you will see all the routing configurations are perfect there might be some issues which is denying the traffic so there is something also you need to check out whenever you are doing troubleshooting your routing concepts so this way we can troubleshoot any type of routing I used static routing here just to use static routing it might be your default routing answer so I'll use one simple example for default routing hassle so let's take an example I have a simple network I got a router land which is connecting to my different branch offices and also it is correcting to my ISP from where I've able to access it down from where I'm able to access internet so my users in my land complaints a user in Milan complains that is not able to access Internet so now there are many things we need to keep in mind whenever this user says I have not able to access internet first thing you have to make sure that you should be able to access the key so make sure that your land users at the Gateway are connecting or communicating with each other by using a simple ping command and then we need to go through outer one and verify the routing table because in order to access your internet routes you should have a default route pointing towards isp with a common next with the next hop address whatever or you can use exit interface also so the default route must be configured correctly ok if there is no default routing or if this interface goes down automatically your default route will be removed in that case they will not be able to access so if you realize that all the users are not able to access then there's mate there is a problem with your centralized device it might be a switch or it can be a router or it might be a problem with isp but if only that fits the users complaints that is not able to access where as everyone can access so you it is the waste of time again checking the routing configuration because if there is a problem is a router routing or ISP then no one should have been able to access so check your configurations on your PC take his connectivity to the lab and check his settings sometimes your wrong IP addresses or it is not able to he's not using the right DNA default gateway + or DNS ourselves all these things so always check those things but a routing part again it's the same thing make sure that you should have a default route pointing towards ISP so these are some of the basic things we need to keep in mind when we do troubleshooting your routing concepts so in our next videos we'll be discussing more in detail about how to troubleshoot your EA GRP and we also see how to troubleshoot it with your protocols which are much more common dynamic routing protocols in approach to networks so thanks for watching [Music]

Channel: Sikandar Shaik

Views: 13,629

Keywords: ccna, ccna videos, ccna tshoot, noa, ccnp, noa videos, cisco, ccie, subnetting, ccna security, bgp, ospf, firewall, ccna subnetting, ipv6, bgp videos, stp, ccna vdieos, ccna free video, ccie certification, ios, iou, virtual, eigrp, cisco virtual lab, iosv, asav, gns3, routing, noa vdieos, noa solutions, zone based firewall, zone pair, zbf, flsm, cisco firewall, cisco security, cisco certifications, wan, ip addressing, netmetric, vlsm, eigrp configuration, vlan, ccnp, noa videos, cisco

Id: Aiayg-8nJx8

Length: 21min 48sec (1308 seconds)

Published: Mon Jan 23 2017