A mac address for a Vlan
Could someone please tell me if a mac address is getting created as a result of creating a layer 2 Vlan?
Thanks..
Just tested this on a Cisco 3750 on my desk.
I had VLAN 1 Shutdown.
I did a show mac-address-table and there was no MAC for Vlan 1.
I unshut the VLAN 1 interface (no IP configured on it) and now there IS a mac-address entry in my table.
Understand that this is different than just adding say VLAN 10 to your vlan database or something like that.
If all you did was add a VLAN (re, not a virtual interface) to your vlan config then it will NOT create a mac-address entry.
However, if you create an interface, it will.
So the answer to your question is, it depends on what you are trying to do.
Hope that helps!
James
Similar Messages
-
I need to change the MAC Address for Airport on MacBook
I have a specific need to change my son's Airport MAC address as his school requires the use of USB network cards that aren't compatible with MACs. These cards are needed because the school's router uses MAC address filtering.
Before we upgraded his Mac to Snow Leopard, we were able to change the MAC address to the MAC address of the useless dongal the school supplied. We basically created an AppleScript program that ran the "sudo ifconfig en1 ether xx:xx:xx:xx:xx:xx" and all was good.
This command no longer works for changing the MAC address. We tried it as root user as well and by typing it into the terminal window as root. After running the command, we can run "ifconfig en1" and it does display the new mac address but when we turn the airport on and try to connect, it just hangs and won't connect.
Our other non-Snow Leopard still works fine after running the commands so I'm guessing Apple disabled this functionality. It's hardly a security issue by being able to change your mac addres.
Is there a new way to accomplish this? I've searched everywhere.
Thanks!Would an easier solution be to provide the school's IT admin with your mac address and have it added? If they can add a block of mac addresses for the usb dongles, they can add more for machines that cannot use the dongle.
Also: "It's hardly a security issue by being able to change your mac address."
While it may not be a security issue for your machine, it is a security for the school network who is using mac address filtering as hopefully only one part of their wireless security.
That being said, have you read this?
http://osxdaily.com/2008/01/17/how-to-spoof-your-mac-address-in-mac-os-x/ -
ARP table not populating mac address for previously reachable IP address
Router has been online and working fine with one BGP neighbor for almost 2 years and no downtime. 2 weeks ago, added a 2nd BGP peer. Everything worked fine for 2 weeks, then all of a sudden yesterday the 2nd BGP peer is disconnected and does not come back. ISP checks and sees everything looks fine on their end. We cannot even ping each other now.
Upon investigation, the ARP table is not even populating the MAC address for the BGP peer IP anymore (same local subnet). Stays "incomplete" in the table no matter what we do, including clearing arp table, changing IP address, etc.
Plug a laptop directly into the 2nd BGP peer FE port and replicate the IP addressing. Laptop cannot ping Router, but Router CAN ping laptop. Check ARP table, but STILL no mac address assigned and now not even the ARP table showing "incomplete".
Thinking it could be the FE interface, switch to the 2nd FE interface and perform same laptop test, this time with arbitrary IP addressing. Now cannot ping each other, no MAC in ARP table.
End up rebooting the router and lo-and-behold, everything is working normally again. 2nd BGP peer peers up instantly.
I should also mention that the 1st BGP peer worked flawlessly throughout, taking all the Internet load and having no issues throughout.
Also, the FE ports for the 2nd BGP peer are on an HWIC FE card plugged into the router. The 1st BGP peer is plugged into the built-in GE interface. 2901 running: c2900-universalk9-mz.SPA.151-4.M4.bin
Lastly, no router resource issues, no error messages, no logs. Just the BGP peer disconnecting.
I have never, in 20 years working with Cisco routers seen something like this before. This is the most fundamental aspect of IP and Ethernet that was not working.
Has anyone ever seen this behavior before??
Here is the router config (IP's changed):
version 15.1
service timestamps debug datetime msec localtime show-timezone
service timestamps log datetime msec localtime show-timezone
service password-encryption
service internal
service sequence-numbers
boot-start-marker
boot-end-marker
logging buffered 150000
aaa new-model
aaa authentication login LAUTHEN local
aaa authentication login TAUTHEN local group tacacs+ enable
aaa authorization console
aaa authorization exec LAUTHOR local if-authenticated
aaa authorization exec TAUTHOR local group tacacs+ if-authenticated
aaa session-id common
clock timezone PST -8 0
clock summer-time PDT recurring
no ipv6 cef
no ip source-route
ip cef
no ip domain lookup
multilink bundle-name authenticated
username ubiadmin privilege 15 secret 4 .JbeuWXuZvchrG0OL.5BftFtqrrEyxcnVHn5rIuCnTk
username umitsnoc01 privilege 15 secret 4 cUmoRUjey9O1x.wk9S.kleX.iAAhCwihupr6Z98p6OA
redundancy
ip ssh version 2
track 1 interface GigabitEthernet0/0 line-protocol
class-map match-any AutoQoS-VoIP-RTP-Trust
match access-group name SIP-Media-INBOUND
class-map match-any AutoQoS-VoIP-Control-Trust
match ip dscp cs3
match ip dscp af31
class-map match-any Customer-Voice
match access-group name Customer-VPNs
class-map match-any media
match access-group name SIP-Media
class-map match-any signaling
match access-group name SIP-Signaling
policy-map AutoQoS-Policy-Trust
class AutoQoS-VoIP-RTP-Trust
priority percent 70
class AutoQoS-VoIP-Control-Trust
bandwidth percent 5
class class-default
fair-queue
policy-map queue
class signaling
bandwidth percent 5
class media
priority percent 50
class Customer-Voice
priority percent 40
class class-default
fair-queue
policy-map shape
class class-default
shape average 10000000
service-policy queue
interface Embedded-Service-Engine0/0
no ip address
shutdown
interface GigabitEthernet0/0
description BGP Peer 1
ip address 2.2.2.2 255.255.255.252
no ip redirects
ip flow ingress
ip flow egress
duplex auto
speed auto
service-policy output shape
interface GigabitEthernet0/1
description LAN
ip address 1.2.3.4 255.255.255.0
no ip redirects
ip flow ingress
ip flow egress
standby 255 ip 1.2.3.1
standby 255 priority 105
standby 255 preempt
standby 255 mac-address 1a2b.3c4d.5e6f
standby 255 track 1 decrement 10
duplex auto
speed auto
service-policy output AutoQoS-Policy-Trust
interface FastEthernet0/0/0
description BGP Peer 2
ip address 1.1.1.1 255.255.255.252
ip flow ingress
ip flow egress
duplex full
speed 100
service-policy output shape
interface FastEthernet0/0/1
no ip address
shutdown
duplex auto
speed auto
router bgp 7777
bgp router-id 2.2.2.2
bgp log-neighbor-changes
network 1.2.3.0 mask 255.255.255.0
neighbor 1.1.1.2 remote-as 5555
neighbor 1.1.1.2 update-source FastEthernet0/0/0
neighbor 1.1.1.2 prefix-list L3-DEFGW in
neighbor 1.1.1.2 route-map L3-LPREF-IN in
neighbor 2.2.2.1 remote-as 6666
neighbor 2.2.2.1 ebgp-multihop 2
neighbor 2.2.2.1 update-source GigabitEthernet0/0
neighbor 2.2.2.1 send-community
neighbor 2.2.2.1 prefix-list COLO-DEFGW in
neighbor 2.2.2.1 route-map COLO-LPREF-IN in
neighbor 2.2.2.1 route-map COLO-OUT out
ip forward-protocol nd
ip bgp-community new-format
ip as-path access-list 5 permit _5555_
ip as-path access-list 5 deny .*
ip as-path access-list 10 permit ^6666$
no ip http server
no ip http secure-server
ip flow-top-talkers
top 50
sort-by bytes
ip route 0.0.0.0 0.0.0.0 1.1.1.2 254 name L3
ip route 0.0.0.0 0.0.0.0 2.2.2.1 255 name COLO1
ip route 10.0.0.0 255.0.0.0 10.10.10.10 name FW_OUTSIDE
ip tacacs source-interface GigabitEthernet0/1
ip access-list standard SNMP_SOURCES
permit 12.12.12.0 0.0.0.255
deny any log
ip prefix-list L3-DEFGW seq 5 permit 0.0.0.0/0
ip prefix-list COLO-DEFGW seq 5 permit 0.0.0.0/0
ip prefix-list COLO-LPREF-OUT seq 5 permit 1.2.3.0/24
route-map COLO-LPREF-IN permit 5
match as-path 5
set local-preference 250
route-map COLO-LPREF-IN permit 10
set local-preference 150
route-map COLO-LPREF-IN permit 20
route-map COLO-OUT permit 10
match ip address prefix-list COLO-LPREF-OUT
set as-path prepend 7777 7777 7777
set community 29795:1004
route-map COLO-OUT permit 20
route-map L3-LPREF-IN permit 10
match as-path 10
set local-preference 200
route-map L3-LPREF-IN permit 20
set local-preference 150
snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart
snmp-server enable traps vrrp
snmp-server enable traps flowmon
snmp-server enable traps transceiver all
snmp-server enable traps ds1
snmp-server enable traps call-home message-send-fail server-fail
snmp-server enable traps tty
snmp-server enable traps license
snmp-server enable traps envmon
snmp-server enable traps ethernet cfm cc mep-up mep-down cross-connect loop config
snmp-server enable traps ethernet cfm crosscheck mep-missing mep-unknown service-up
snmp-server enable traps flash insertion removal
snmp-server enable traps mac-notification
snmp-server enable traps aaa_server
snmp-server enable traps cef resource-failure peer-state-change peer-fib-state-change inconsistency
snmp-server enable traps memory bufferpeak
snmp-server enable traps config-copy
snmp-server enable traps config
snmp-server enable traps config-ctid
snmp-server enable traps event-manager
snmp-server enable traps hsrp
snmp-server enable traps cpu threshold
snmp-server enable traps rsvp
snmp-server enable traps syslog
snmp-server enable traps vtp
snmp-server enable traps ipslaWhen you were checking the ARP table was there an entry for Fast0/0/0?
HTH
Rick -
How do I find the Mac address for my 8900?
I have a wireless network and can't connect to it at all. I have looked and typed in Blackberries search engine and came up with nothing, only answers are about a MAC computer, not what I am looking for.
I have to add the Mac address to the wireless network in order to get past the firewall and this is not working for me, any ideas.
Thank you,
Animal
Raising teenagers is like trying to nail
jell-O to a tree!Found it,
Overview
To find the Media Access Control (MAC) address of a Wi-Fi® enabled BlackBerry smartphone, complete the following steps:
Click Options.
Click Status.
The WLAN MAC field displays the MAC address for the BlackBerry smartphone.
Raising teenagers is like trying to nail
jell-O to a tree! -
IP-4-ZERO_ADDR: Zero MAC address for ip in ARP cache
Could someone hlep me with this log message: IP-4-ZERO_ADDR: Zero MAC address for <ip> in ARP cache
It just started appearing in our Cisco 10012 CMTS, and all of the documentation is very vague as to what it is and how to fix it. I'm hoping someone else has seen the message and can help clarify it's meaning. Thanks in advance!Your not the only one with these logs mess :
Jan 20 13:05:10: %IP-4-ZERO_ADDR: Zero MAC address for 10.100.xxx.69 in ARP cache
Jan 20 13:30:02: %IP-4-ZERO_ADDR: Zero MAC address for 10.100.xxx.69 in ARP cache
I thing the reason is that someone has a worm or something ping-flooding/scanning the network, check your arp table for incompletes.
What to do about it, disable icmp on the network maybe, for now we dont have a problem on the network but would be nice to fix this thing.
Martin
DK -
E4200 v2 - Uses multiple MAC addresses for the same device
This unit seems pretty good at first but on looking at the Web interface I noticed that it was using multiple mac addresses for the same device and showing devices on the lan on the Wireless side and other odd things.
After a week of running it the home server network started to get erratic, it would seem to all point to dns and dhcp issues in the router.
Seems the V1 had the same issues that they did not fix on this.
The Cisco connect software shows 5 devices the Web based utility shows 3??.
Its pretty bad that they charge nearly $200 and cannot be bothered to finish the unit or address the issues that were in V1.I am afraid I didn't get the clear picture of the issue mentioned in the post. Could you please elaborate a little bit? If you connect a device/computer wired and then later you connect it wirelessly. It is obvious that you would get to see two different MAC addresses for the same device, one for the LAN adaptor and other one for WLAN adaptor. If that is what you are referring to?
Secondly, may I know, what issues did you face with DNS and DHCP in the router? Is it not able to resolve the DNS or something else or DHCP is not sending IP address to the clients? -
How do I find the MAC address for the time capsule?
I am trying to install 2T time capsule as my main router. Telus my internet supplier allows me to in install the MAC address for the static ip that I am going to use. But where is the MAC address on the cube or how do I get it?
On the bottom label it should list the MAC address.
If you happen to still run the original.. ie decent airport utility it has all that info right in front of you.
But you see that was before Apple reduced the airport utility to the status of a toy..
Pretty pictures no info.. think kid's book.
See very very pretty.. as a UTILITY though.. useless. -
MAC Address for iPhone on Network?
In order to keep riffraff from sniping my wireless internet connection, I am setting my network connections to only allow the specific MAC addresses of the computers in my home to connect to the internet. Do I have to do the same thing to my iPhone? If so, where would I find the MAC address for my iPhone?
Settings/General/About/WiFi Address.
-
I have just received my first Apple product and need to get the device MAC address for my router connection. Can anyone tell me how to get it.
Settings->General->About->WiFi Address is your mac address.
-
How do you find the phone's mac address for Droid RAZR Maxx HD?
how do you find the phone's mac address for Droid RAZR Maxx HD?
Ann154 wrote:
WalrusM wrote:
how do you find the phone's mac address for Droid RAZR Maxx HD?
It is listed under the advanced options for the WiFi settings or About Phone > Status within the phone's settings
Motorolas list them under About Phone > Status.
Edit: Oh, snap! It is listed in both places. Nevermind! Please excuse! -
How to find MAC address for WAN port for Airport Express 2nd Gen.
The New Airport Express has a LAN and a WAN ethernet ports. How can I find the MAC address for the WAN ethernet port as my Service Provider needs it for provisioning....I can fid MAC address for Ethernet and for two wireless 2.4 & 5GHz but not for WAN ethernet port using Airport Utility 6.1
Many thanks for the swift response. However, there is no WAN MAC address on the box or on the device anywhere. I even used magnifying glass to find one .
The airport utility shows only three mac addresses. One for 2.4GHz, one for 5GHz and one fo the ethernet (LAN port) whereas there is another ethernet port in the device mentioned as WAN port and I am still not able to find the MAC address for the WAN ehternet port for Airport Express (2nd Generation).
Will appreciate a response to make th device work wiht my service provider as providing them the WAN mac address is a must. Had there been an option for cloning mac address, the issue would have not been there.
Many thanks again - in advance. -
MAC address for HP PRO CP1525NW
I want to enforce MAC filtering in my router.The OS is win7 home pro 64 bit.
How do I find the MAC address for my CP1525nw printer? It is not on the label, and the router reports only the name of the printer.
This question was solved.
View Solution.First, MAC filtering is not a security measure because it is so easily defeated. Read more here: http://blogs.zdnet.com/Ou/?p=43
If you want to continue, print a self test from the front of the printer: Reports > Config Report. It will be listed as the Hardware address.
Say thanks by clicking "Kudos" "thumbs up" in the post that helped you.
I am employed by HP -
"failed to get MAC address for machine"
here is the jist of things.
installed leopard and have it pimped out to my personal specs. I like where everything is and how things are working. No issues. just so you know, i only use WIFI for internet, i share with the guys upstairs. In order to get wifi on my machine, i use a USB dongle. works great no issues with it ever, well until i physically broke it. No big deal. So i replaced it with another one, different drivers/chipset worked.. And since i installed leopard i only backed it up once with TM, i dont care for daily/hrly backups, weekly is fine for me. Now after 2 weeks and a new usb network card. TM gives me an error. i click on the little red i and it says "the backup volume could not be found" so googled and searched the forums not much help, so i tried and formated my ext drive repaired and click on TM again, same error. In the error log in console, right after i turn on TM i get this error, "failed to get MAC address for machine" then 180 secs later, TM fails. again, and again.
Can anyone tell me where i can find what MAC address its looking for??? ethernet has never been plugged in to my machine ever. its only been online via USB wifi. Im really lost here, i dont know what i can do.. im sure if i try another drive ill get the same error. please help if you can.. much appriciated.
Jamieyeah i get a 'failed to get mac address' message too. what's weird is that it seems that leopard 'broke' my ethernet (there was no mac address, couldn't connect to the internet through ethernet after a clean install), and then 10.5.2 'fixed' it. for some reason, i have an 'ethernet 2' heading in system preferences that works correctly and has a mac address and everything, while the regular 'ethernet' tab doesn't work at all. however, i still get this time machine error. i don't understand why time machine is so incredibly fickle. sorry, i'm really of no help to anyone, other than adding another voice to the frustration.
-
Mac addresses for vlans along trunk links
Hi all, can anyone tell me, if I have 2 switches, both connected to a distrubution switch, both access switches are on different vlans, I i ping a device on the other subnet which is a vlan on the other switch, am I right in saying the mac address of the destination pc will never but put on the source trunk as its routed across the distribution switch.
can anyone help ?You are correct. When PC1 which is on VLAN1 attempts to ping PC2 on VLAN2, PC1 in your case would use its MAC as the source and the MAC address that is associated with the distribution switches VLAN1 ip interface.
The distribution switch would then route the packet to VLAN2s ip interface which would change the frame by removing the source mac (which was orignaly PC1) and adding its own source mac and change the destination MAC to PC2 -
Hello everyone,
i have a network with a
L3(core) 6500 12.2.3(33)SXH5 with vtp (server) and pruning on, rstp
L2(distribution, ) with 3750 fiber connected
L2(access) with mixed hardware 2950-3750
when i go to setup a rspan:
6500(config)#vlan 400
6500(config-vlan)#remote-span
access(config)#monitor session1 source remote vlan400
access(config)#monitor session1 destination fa2/0/1
access(config)#monitor session1 source int gi1/0/37, gi1/0/44, tx
access(config)#monitor session1 destination remote vlan 400
my problem is on a periferic access switches 2950 not redundant:
i relevated a
duplicate mac-address table, i found a every mac on 2 vlan, the 200 and 400(of remote span) with related problem of loss of packets and random connection problem
My question is:
is compatibile the rspan with 6500 vtp, how i can fixed this problems?
thank youOther users from the forums with a similar problem came to a conflict occurring here
Oct 18 11:52:41 MacBook-Pro opendirectoryd[123]: 2595.39 - ODNodeCreateWithNameAndOptions failed with error 'Unknown node name' (2000)
They say it's some sort of conflict with the language of the installation or is it language keyboard input, then what is meant and how it can be solved I do not understand if this is certainly so.
(sorry for my bad english)
Maybe you are looking for
-
On my imax, all of a sudden I am unable to send original emails with attachments of any size. I can attached the file but when I try to transmit, it will not go. Also, if I am emailing back and forth, once there gets to be several threads, it will n
-
How do I get the activity bar back in Lion Mail 5.3
I tried installing mountain lion unsuccessfully over Lion on my 27" imac (16 gb RAM) i7 quad core, 2012 model. I couldn't do anything to make it load. It would say installation finished but upon startup the grey screen with rotating circle never q
-
Trying to transfer songs from iPhone to my iTunes. Help!
I had iTunes with lots of songs and all of the songs are on my iPhone. Last week my computer crashed and I had to replace my hard-drive and memory, so I lost all of my music. I am trying to get all of my music back onto my computer and into iTunes. S
-
Clear customize Date field value in workflow using IDOC Script
hi all I have a customize field type is Date with default value is Current date time. At one step of workflow I want to clear the default value of this field with <$wfUpdateMetaData("xmPublicDate", "")$> But it not effect. The current date time still
-
Error Report on Duplicating Elements
An Error occured after duplicating an Elements. If you right click any item on the Elements it will show you an Error Message "An error occured. Please save your work and restart Edge Animate.".. Below are the steps to get the Error: 1. Right click a