07-04-2013 08:27 AM - edited 03-04-2019 08:22 PM
Hi guys, here's the scenario
PE MAC Address is : 80:71:1f:44:da:f4 and CE MAC is : 00.06.f6.e8.89.70.
However we are still not able to reach the remote end.
PHSDCOTAUPH01R02#sh arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.185.0.133 0 Incomplete ARPA
Internet 10.185.0.134 - 0006.f6e8.8970 ARPA GigabitEthernet0/0.910
why is it that i can't learn PE mac?
thanks
07-04-2013 08:45 AM
You are not getting ARP replies from PE, you don't have the full layer 2 connectivity, check with ISP.
Sent from Cisco Technical Support Android App
07-04-2013 09:07 AM
This is actually details coming from PE side which both mac is learnt.
ULC Mac address Interface/Circuit Type Age(sec)
---- ----------------- ------------------------------ ---- --------
1/5 00:06:F6:E8:89:70 ge-1/5/3/2.910 D 166
1/9 80:71:1F:44:DA:F4 ge-1/9/2/4.910 D 252
and i've actually configured L3 on its L2 settings, i actually been able to ping WAN ip.
fyi, this is actually the problem from my client where ISP has no problem only they can't learn the mac on their PE side.
07-04-2013 08:46 AM
Josiah,
All that means is that your CE router has tried to resolve the MAC address of10.185.0.133 and for whatever reason it failed. There are many reasons why that would happen. If it is not a physical problem then it could be that the address is not configured on the other end of that link. Or if your provider expects you to dot1q tag your traffic then that would also cause it.
07-04-2013 11:00 AM
Couple of things that is needed:
How is the Provider connected to you, what is the topology?
What routing is in place or are the IP's a part of a directly connected interface?
Is the interface up and line protocol up on the interface facing your provider?
Can you ping anything beyond the provider?
From the CE router can you see anything on your internal network?
From the CE do you have a default route or default-gateway configured?
07-04-2013 12:47 PM
Look:
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080094adb.shtml
======================================================================================================
Add Mac of interface neighbor ( ISP )
R1(config)#arp 10.185.0.x aaaa.bbbb.cccc arpa alias
07-04-2013 11:48 PM
Here's the checking from our client below:
1. Single tag at PE and no tag at CE
2. Single tag at PE and single tag at CE
If using 1., then PE can see CE MAC, but CE still cannot see PE MAC, thus, CE & PE cannot ping each other,
If using 2., then PE and CE cannot see MAC of each other, thus, CE & PE cannot ping each other.
Currently, PE is setting double tag & CE is setting single tag as following. Both cannot see each other MAC.
Please further check it.
PE router:
ME2# run show configuration interfaces ge-5/2/0.10
vlan-tags outer 910 inner 910;
family inet {
mtu 1500;
no-redirects;
address 10.185.0.133/30;
}
{master}[edit]
ME2# run show arp | match 5/2/0.10
{master}[edit]
CE router:
Router(config-subif)#do show run | s GigabitEthernet0/0
interface GigabitEthernet0/0
description link to PE: DTAC to update circuit ID
bandwidth 4000
no ip address
no ip redirects
no ip unreachables
no ip proxy-arp
load-interval 30
duplex full
speed 100
no cdp enable
hold-queue 32768 out
interface GigabitEthernet0/0.910
encapsulation dot1Q 910
ip address 10.185.0.134 255.255.255.252
no cdp enable
PHSDCOTAUPH01R02(config-subif)#do show arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.185.0.133 0 Incomplete ARPA
Internet 10.185.0.134 - 0006.f6e8.8970 ARPA GigabitEthernet0/0.910
What's next course of action for this? thanks
07-05-2013 07:03 AM
you can not see MAC of ge-5/2/0.10.
use show interfaces:
CPDVG01#show interfaces gigabitEthernet 0/1
GigabitEthernet0/1 is up, line protocol is up
Hardware is BCM1125 Internal MAC, address is aaaa.aaaa.aaaa (bia 001c.f6f1)
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 2/255, rxload 2/255
-- more --
after:
R1(config)#arp 10.185.0.x aaaa.aaaa.aaaa arpa alias
abs.
07-07-2013 07:24 PM
The ge-5/2/0.10 interface is actually connected on their PE router, so do i need to define this command "R1(config)#arp 10.185.0.x aaaa.aaaa.aaaa arpa alias" on their CE router?
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide