Questions tagged [arp]
For questions about Address Resolution Protocol (ARP). ARP resolves OSI layer-3 addresses to OSI layer-2 addresses.
371 questions
8
votes
4
answers
546
views
Switch losing ARP table and broadcasting unicast packets
We have a setup with four equipment connected to an EX3400 PoE switch.
One is a linux server with IP 10.10.0.101.
Two are custom FPGA boards - let's call them A boards - with IPs 10.10.0.150 and 151 ...
1
vote
1
answer
110
views
When a layer 3 switch or a switch with SVI receives a broadcast frame, does the switch decapsulate the frame?
When a layer 3 switch or a switch with SVI receives a broadcast frame, does the switch decapsulate the frame? I was confused on this. I was playing with packet tracer trying to get a better ...
- 11
1
vote
0
answers
46
views
alternatives to a bridged wlan connection for a libvirt host [closed]
I need a qemu vm to have a stand alone private ip on my lan. I only have a wifi physical device. NAT mode won't work as I need the guest to have it's own ARP table.
I'm seeing non-unique MACs on my ...
- 111
2
votes
1
answer
234
views
Do echo replies typically send out an ARP request?
When a host receives an ICMP echo message from an unknown IP on the same subnet, would it send an ARP request to determine the IP's associated MAC address? Or would it simply flip the source/dest MAC ...
- 21
8
votes
5
answers
4k
views
Why don't routers answer ARP requests for IP addresses they can handle even if they aren't assigned that IP address themselves?
An ARP request is made to know the MAC address of the device that has some specific IP assigned. This way we will be able to know what MAC address we should set to send out IP packet.
If a device ...
- 299
1
vote
2
answers
713
views
Unable to ping/Scan Profinet PLC Device Through Siemens SCALANCE X108 connected to Cisco VLAN-Based Switches
I'm facing an issue with network connectivity to a Profinet PLC device and would appreciate some help. Here's the setup:
PC ↔ DLINK Switch ↔ Cisco C2960 ↔ SCALANCE X108 ↔ PLC Device
Only Managed ...
- 21
1
vote
1
answer
210
views
Why do routing tables and arp tables both require a field of interface?
Routing tables are queried using destination IP of a packet to get the next hop IP and to get the interface to send the packet through.
But since the router will strip the ethernet header first and ...
- 53
1
vote
1
answer
160
views
What happens to ARP replies if a switch connects to a router directly over one interface and indirectly over another?
Very typical topology:
R1 --- R2
| X |
SW1 - SW2
| |
H1 H2
(The X represents SW1 connecting to R2 and SW2 to R1)
Switches 1 and 2 both connect to R1 and R2 (e.g. for FHRP).
When H1 ...
- 25
0
votes
1
answer
614
views
why does "show arp" on my Juniper EX3400 return empty?
JunOS version is 20.2R3.9.
For instance:
root@CLEANROOM-IDF-D8> show arp interface ge-0/0/4.0
{master:0}
root@CLEANROOM-IDF-D8>
...what gives? There is a device on that port and it's working, ...
- 3
1
vote
2
answers
130
views
Missing ICMP identifier equivalent in ARP protocol and desired arping behavior
Running simultaneously more arping on the same interface and the destination IP address all clients get the responses due missing ICMP identifier equivalent.
First, am I correct that there is no ICMP ...
- 147
6
votes
3
answers
887
views
Can ARP tables store addresses for other networks?
This is perhaps a weird question, but I'm in a weird situation where I want to route traffic from network A 192.168.1.0/24 to network B 192.168.2.0/24 via 192.168.1.5 (the address of B-router in the A ...
- 163
0
votes
1
answer
89
views
Scenarios in which a host (e.g. Debian) would update its ARP table [closed]
For security reasons, I'd like to know for which of the following scenarios would a host (Debian for example) update its ARP table:
It receives a gratuitous ARP for IPs that are not in its ARP table
...
- 283
2
votes
1
answer
262
views
which protocol is invoked first by routers ? routing (routing table) or ARP?
I have a question regarding the internet layer of the TCP/IP model: When a data frame is sent by a client to a server located on another network, we know that the routing tables and the ARP protocol ...
- 33
0
votes
1
answer
438
views
Can't ping between cabled interfaces on different VRFs on same switch (Cisco 3548)
As an experiment I've created a non-default VRF, directly cabled between an L3 port on the default VRF and an L3 port on the non-default VRF, and am trying to ping between them. Neither interface can ...
- 101
1
vote
1
answer
98
views
Reverse ARP In Data Link Layer
In the arp the Mac address is used as a broadcast address with a value FF:FF:FF:FF:FF:FF as the destination hardware address. But What about reverse ARP broadcast address? Which broadcast address ...
