How Is A Computers Hostname Translated Into An IP-address
May 15, 2011
How is a computers hostname translated into an IP-address?Eg. when i enter "\server1" into the "run"-menu i get access to my server at IP-adress 192.168.1.2, but how does my computer know what IP-address is it?
I am having trouble with getting a copier that I have networked to stay registered in the system. When connecting all the equipment back for the new year I was having trouble getting this one specific copier back online properly. I used to have it assigned with a static IP because the person that was here before me had all the computers map the printer using the IP instead of Hostname but that was causing IP conflicts so I removed it and mapped the printer through Hostname which is made "MPF-TOSHRM328"So now for the actual problem, after the copier got the new dynamic IP of 10.8.214.151 i thought it would be fine and everything would click in because it was mapped to the host name and not the IP. But when I do a tracert on the hostname it still shows up with the old IP. and now that the old ip has been reassigned it actually points to a physical machine now. Weird. All attempts to flush the DNS have not resolved the issue. I even tried going in and deleting the entries in manually. No luck. As a point of reference here is the result from the tracert.Tracing route to MFP-TOSHRM328.78B450.nycboe.org [10.8.214.126] over a maximum of 30 hops: 1 <1 ms <1 ms <1 ms SLS330W09 [10.8.214.126]Trace complete. I should also mention that this server is only here in the sense that it is the DC for the computers on this floor. There is a whole other system that assigns the IP's and handles the DNS. I do not have access to it, it is run by the main network people at the central offices.
we use LMS 4.2.1 and we noticed a strange behaviour when starting a discovery. From aprox. 160 devices some devices are displayed as IP Address instead of hostname. Every device is DNS resolvable and has a value for "hostname". I´ve tried every possible option in the global discovery settings but some devices have the IP instead of their hostname. how to fix this?
Is it possible on an ASA 5500 device to connect an IPSEC tunnel via hostname instead of the IP address? I have a site without a static IP address that is currently connected via Easy VPN but I want to change one of the sites to a regular IPSEC site to site as one side, the one with the dynamic IP, is being changed to SonicWALL. I will have DDNS setup on the site with the SonicWALL so I want to know if I can point the ASA device to the hostname instead of the IP.
I would like to have these commands on our Firewall to avoid at least several students to use this service. How to translate this? It's apparently working great if I will use an Linux box or another firewall compatible with iptables.
We are migrating from a nother brand to an ASA Cluster running 8.4.5
We have a web-server on an inside interface listening on a non standard port - 20111. We have created a static NAT translating the public ip to the private, so If I do http://public-ip:20111 it works. (we are using a seperate public IP for this service only).
Now I need to create a NAT rule that will forward requests on BOTH port 80 and 443 to the same private ip and the same port number (20111)
The Private address is 10.99.250.20 and the "public" (I've replaced it in this example) is 172.16.16.16 I have managed to create a NAT that will translate 443 to 20111:
I want to set up a Home network between a Win XP PRO/LINUX UBUNTU 10.10(Dual boot) and a Win XP PRO.I need to find out:
A) The IP address of:
1) Each machine on the router
2) The router's IP address
B) How to configure the router using this information Several years ago I saw a tech set up a network using this information but I don't remember how to do it
C) What software I can use on Ubuntu to set up the network
I have a Windows 7 computer. My boss changed the IPv4 address of this computer. Nowalthough all computers can connect to the network, they can no longer see this computer. And this computer cannot connect to the other computers.
here where I work we are having an issue with IP Address conflicts. We are not sure exactly why, though. We have only had it happen 2-3 times so far, but this has been over the past week or so, and we would like to get it resolved. Here is what is happening: Last week we were getting an "IP Address conflict" message on one of our computers. It had received 192.168.3.112 from our DCHP server, so we switched it to a static IP address up beyond our DHCP range. We then tried pinging the address with the conflict, but got nothing. We figured it was some device that had a static address, so on the DHCP server we reserved it to a non-existent mac address so it wouldn't hand that one out again. This wasn't a problem, since it was an isolated incident.
Since then we have tried periodically pinging 192.168.3.112 to see if there is actually a device using that address, but have gotten no replies. Since then we have had another one or two times where this has happened, but with different IP addresses. We went around and checked a couple of different wireless routers that we had deployed, but the DHCP had been disabled on all of them (but then again, the issue came up just recently, while the routers have been out there for months).
Bought DIR-655 from Amazon. Rev. B. Come with 2.00NA firmware. Updated to latest one, and there are a lot of problems, to most of them, I was not able find any solution. Here they start:
1. WIFI SPEED PROBLEMS.No matter what speed, parameters, channel, mode, etc I select, router keeps working on 20mhz channel width. So I never get speeds above 65 mbit. In absolutely same conditions, my DIR-300 B1 (with DD-WRT firmware) gives me stable 150mbit. SO I KINDLY ASK, MAYBE THERE IS A WAY TO FORCE "40 MHZ ONLY" OPTION?
2. PASSWORD PROBLEMS.Router came with no admin password, I enter new password, hit "update" it says - wait 20 sec, after that, login page is displayed, but, new pasword does not works! since it asks again for empty password!
3. FILTERING PROBLEMS.I need to block certain IP address to be accesed by all my computers. Say this is 111.111.111.111 . So I added inbound filter rule, to block access to that IP. It does not works - IP is still accesible.
4. MORE FILTERING PROBLEMS.Since above mentioned method does not works, I have to use "ACCESS CONTROL" feature. It does works, but it causes another problem, with access control enabled, all webpages with form submit stop to work. For example, if I'll have that feature enabled, when I press "post" on this webpage, it instantly will go to "this page cannot be displayed".
I bought this router solely for one purpose - I was happy with speed of my DIR-300, but I needed gigabit for my computers. So I thought, instead of buying separate switch, I'd better buy a router with gigabit. I was suggested to get TP-LINK 1043, since it's quite popular, alternate firmwares available and so on, but I refused to buy it, since I thought that some chinese company does not worth my attention. So I bought this D-Link (for almost 2x price of TP-Link) and having huge problems as you can see.
I want to do what I thought would have been a simple enough task - block my kids phone/computer after certain hours. Instead of blocking the specified MAC address(es), all my computers does not have internet access. As soon as I disable the policy, internet access is on again. Here's what I did:
when I ping another workstation on my local network I should get back it's local IP but instead I am getting an ip address that resolves to somewhere in Germany! In fact if I ping any bogus name, I mean anything, it returns this same address 62.116.181.25. If I shut down my cable modem then everything resolves correctly. And yes I have DNS relay enabled because it seems to be the only way to get the workstations to resolve external sites correctly.
Everything in our small network worked until today when I had to manually reset the router. We run a application through a provider which requires that we view it from the same IP address for access. We have a statis IP assigned by our ISP solely for this purpose. For simplicity, lets us 23.11.23.176 as the statis assigned by our ISP and 23.11.23.175 as the gateway also assigned by our ISP. The application we need to browse requires that we use the 23.11.23.175 address else it is blocked from viewing. When we hard line into the modem, we are able to browse it fine. When I connect the CISCO router and do it wirelessly, it shows our address as 23.11.23.176 what are the required steps in order to set the CISCO router to use the Gateway address as the browsing IP for computers connected to it. We had set it up about a year ago, and i completely forgot how.
I am administering a Catalyst 2960S switch and I would like to connect several computers to it. Some of those each have a static IP address. For a few of them, I would like the switch to dynamically assign an IP address to them via DHCP. Is the switch capable of doing this? If so, how can I do it? I tried looking through Cisco Network Assistant and I couldn't find it. Some web pages have suggested I telnet into the switch and issue commands like "ip dhcp ?" to see what commands are possible. I can telnet in and if I type but I get an "Unrecognized command" for both "ip ?" and "ip dhcp ?". This makes me think I'm reading the wrong web pages. I did come across the term "DHCP snooping". It seems relevant, but very difficult for me to grasp.
I have Windows 7 x64 on my desktop, laptop, and HTPC. The past few months, everything worked fine. Today, I can ping my IP address but I cannot ping the host name on all 3.They also do not show anything in the network window, just the computer that I'm on.
We have one business application, accessed across GCC region by having a single entry with individual computer hosts file, ie123.123.155.116 myappl.mycompany.com and other than Bahrain, all countries are able to successfully resolve the hostname (application only works against hostname (Oracle EBS)) against this entry with the hosts file. Now, prior contacting the ISP in Bahrain (where internet is regulated due to the current political situations) we need to know whether anything could be done from our end to resolve this issue.
I have a small workgroup at home of about 4 or 5 computers. All the PC's, notebooks are running W7. I have one PC that I use as my "always on PC", with all my media and resources I use on it. The NetBIOS or computer name assigned to it is mediapc with a static IP of 192.168.254.150. All my other desktop PC's, excluding the notebooks, have a static IP also.The problem is more annoying then anything, and thus I only work on it intermittently. Today I decided to post after wasting much of another day attempting to resolve the issue.The problem is accessing my mediapc from any of my other computers while using the computer name, "mediapc". If I use the static IP assigned above, there is no problems. Everything works, RDP, Dameware, Telnet, SSH, Ping,Tracert, etc. If I use the computer name "mediapc" then it fails with an unreachable host error or similar. The reason it fails is because somewhere in my network or in the mediapc itself, it wants to resolve the "mediapc" name to an unknown IP of 192.168.254.47.
Now with this said, I can still share files and access the mediapc using the name in a UNC syntax, like //mediapc/data works fine or directly clicking on the mediapc share under Network works also. If I Ping mediapc from any other PC than itself, it fails with the 254.47 IP. If I try to use any remote connection software and use the name mediapc, it fails to connect.This is what I know and have tested:
1. Adding a host entry to all the client computers works but does not fix the root of the problem.
2. nslookup mediapc reports the wrong IP of 254.47
3. Remote connections as I mentioned above fail because the name is resolving to an invalid IP.
4. Pinging mediapc from itself, displays the correct IP of 254.150, although I have to use the -4 parameter.
5. Arp -a on all PCs report correct IP of 254.150 with the correct MAC address. (There is no 254.47 listed)
6. NBTstat -a mediapc reports correctly and shows the correct MAC address.
7. Network shares work correctly from and to the mediapc without issue. No access problems.
8. I have deleted all arp entries and flushed the dns with no change.
9. MS mentions to change order of the Bindings of the adapters, yet I only have one Local Area Connection.
I manage the network of a small (120 users) network spread out over 5 sites within a 10 mile radius (for normal ops- extended ops can expand to include other cities).I think I'd call that a Campus LAN, perhaps it's just a really small MAN (for normal ops)...I am starting my CCENT/CCNA track so this may be blazingly obvious to some of you- but I'm sure to learn something either way...Every now and again we have to go find "hostname "X"" for an update that won't roll out by way of our (Server Sr SysAdmin's) tools, so we actually have to put hands on it. Unfortunately the prior admins didn't document the inventory to such a level that we know "laptop_015" is in the building down by the college.
I DO have documentation on my equipment (I'm the Network Sr SysAdmin) that I have rolled together over the last 9 months being here...I have a Cisco 5520 ASA, and use ASDM to manage it. What would be extremely handy would be the ability to put a query in the system to report back what switch a given hostname is plugged intoBetter yet, if it could tell me switch and switchport.I imagine this would be simple if I had the MAC address- there's got to be a way to grep the switches for a given MAC- but not sure if it'll work in a similar fashion for ARP lookups.
is there any way to apply hostname or object network in the syntax? The command gives the option to use hostname or A.B.C.D but doesn't accept the hostname PIX1(config)# filter url except 0.0.0.0 0.0.0.0 ?configure mode commands/options: Hostname or A.B.C.D The address of foreign/external host which is destination for connections requiring filtering Can an FQDN be used as a foreign/external host?
Our Cisco team does inventory pulls with CNC and i was informed that this uses the hostname field currently the report pulls the IPadress, the discoveries that run on the LMS populates displayname field and puts the IP address in the hostname field. is there anyway to update this via query or process, i have too many devices to manually update this.
I'm trying to use MRTG and SNMP on a Windows Serveur 2008R2.I want to manage my Switch with mrtg, but it don't show me which computers or server are connected to the Switch's ports.All I have, in the .cfg file is the interface name ( like S0/0 ), which are useless for me, I would like to get IP adresses or hostname but mrtg doesn't seems to do it.Any of you know if Mrtg can do that ? or maybe there are some others ways to do that ?
As far as I understand it Fault Manager need to be able to do reverse lookup for ip adresses to show the correct name in the "device name" column. I have double and tripple checked and all devices that only is shown as an ip address do have a reverse in the dns used by the LMS server. The device is correctly registered and inventory have been run. If I hold the mouse pointer over the crosshair on the row of the offending device all info is shown including correct device name and fqdn.
The server is upgraded from 4.2.1 to 4.2.2 and we have the same problem before the upgrade.
I have a new 1262AP configure hostname prompt, “APacf2.21c6.820e# lwapp ap hostname ccsaa ERROR!!! Command is disabled.”does not change the hostname of the AP to the WLC, this is why?
My router/modem is a DSL-2740BI created a hostname [URL] At my service provider I was able to create a DNS setting where I specified my routers IP address.In my router I think I created a port forward (TCP port 8080 on both external and internal) with the ip address of a small "web server" (an Arduino module for home automation).When I enter my hostname I get to see my router config page instead of my "Arduino page".
i successfully configured my befsr81 router hardware version 3.1 with a dyndns hostname account. how often is it supposed to update? it doesnt seem to update till i login to the router through my browser. where is successfully updates. is there a way to choose how often it updates?
I am working with an ASA5505. I have configured a Remote Access IPsec Connection profile. This profile is configured to give clients a virtual ip address via DHCP as shown in this configuration example: url...When the DHCP request is sent from the ASA to the DHCP server, the hostname in the request is set to the name of the IPsec connection profile and a number. Is it possible to have the hostname set to the host name of the client that initiated the connection?Does the ASA support receiving a hostname as part of a IKE Mode Config Request?
we are running LMS 4.0 on Windows Server 2008, and just changed the hostname of the server, as the former on reflected it being a test system. However, after rebooting the server (as required by windows), the LMS application did not launch.After rolling the windows server back to the old hostname, the LMS started working again.Why is this? Isnt it possible to change the server hostname after the LMS has been set up for the first time?
I am unable to login to switch c3560 through Hostname but able to login through IP address. when i am putting the command : login authentication telnetpwd
getting the below message:
AAA: Warning authentication list "telnetpwd" is not defined for LOGIN.
I am having issue with my network as my router won't resolve most of the hostname of the network, I have 30 devices on my network, and only 4 names are displayed on the available local host. It makes it very difficult to identify the devices on the network.
I have a big problem with my Cisco EA6500 router. I have a domain that is pointing to my public IP address of the home network. I have various computers and applications that listen on different ports for various reasons on this network. Everything worked fine until a week or so ago when I had to restart the router. The reason was that while I did a routine change (add a Mac filter for wireless) the router stopped responding. After restarting it, I could not access the home computers through the domain name (public IP) while being inside the network. If I try from outside my LAN it works fine but when trying from within the LAN the hostname and IP are not reachable. Also, everything works from inside the LAN if I'm using LAN IPs.