Questions tagged [icmp]
For questions about the Internet Control Message protocol.
143
questions
1
vote
2
answers
62
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
-1
votes
1
answer
68
views
Why MLS2 Doesn't Get ICMP Packet To Where It Should?
This is a Packet Tracer lab from Kieth Barker's website with minor modifications. It is intended to exhibit how can we get to the network 10.10.0.0/24 access to the Web Server 23.1.2.2/24 Using NAT.
...
- 285
0
votes
1
answer
87
views
In wireshark, why following a TCP or UDP stream does not remove ICMP packets?
In Wireshark, when I follow a TCP or UDP stream using right click -> Follow -> UDP Stream, if there are some ICMP packets from same endpoints, wireshark will keep them in the stream. Why? Since ...
0
votes
2
answers
99
views
Do destination hosts decrement the TTL?
I was trying to understand more about traceroute when I stumbled upon this site and I have a question about this diagram:
As you can see in the diagram, the destination host S1 receives a packet ...
- 491
0
votes
1
answer
122
views
In a trace route, do routers that do not respond still forward the packets?
In traceroute,
The sender expects a reply within a specified number of seconds. If a packet is not acknowledged within the expected interval, an asterisk is displayed.
Pasting here the example trace ...
- 491
1
vote
1
answer
90
views
The TTL and packet drop [duplicate]
I would just like to verify one thing. When a router receives a packet with a TTL of 1, the router can still process and accept it if its destined for itself, correct? Because for example, eBGP ...
- 877
0
votes
1
answer
89
views
BGP configuration multi-hop ping not working
I'm learning bgp and studying on a simple lab I'm unable to ping a loop0 two hops away while the loop0 on the nex-hop router is reachable
Topology is simple R3-R1-R2, from R2 i'm able to ping loop0 on ...
- 5
0
votes
1
answer
1k
views
Why am I not capturing any ICMP packets on wireshark?
I am doing a lab where we are meant to ping an address and use wireshark to capture ICMP packets when we ping that address. WHen I run the wireshark capture with the ICMP filter on and ping my address,...
0
votes
1
answer
97
views
Change source and destination adresses from a valid captured ping to create a valid ping with different source and destination
I want to create traffic in my network, especially
I want to send a repetitive ping to the device with the IP 192.168.3.146 from my traffic generator (IP 192.168.3.100) (see scematic)
For the creation ...
0
votes
1
answer
142
views
ICMP error message's data for IP datagram with < 64 bits payload?
RFC792:
The internet header plus the first 64 bits of the original
datagram's data. This data is used by the host to match the
message to the appropriate process. If a higher level protocol
uses ...
- 111
0
votes
2
answers
496
views
IP packet expired by TTL generate an ICMP response in any case?
Acording to Wikipedia IPv4 article for TTL header field:
An eight-bit time to live field limits a datagram's lifetime to
prevent network failure in the event of a routing loop. It is
specified in ...
- 103
2
votes
2
answers
4k
views
Is DHCP in the application layer or the network layer?
Tanenbaum's Computer Networks says:
5.6 THE NETWORK LAYER IN THE INTERNET
...
5.6.4 Internet Control Protocols
In addition to IP, which is used for data transfer, the Internet has
several companion ...
- 1,555
1
vote
1
answer
530
views
ICMP codes in response to ICMP traffic, not UDP/TCP
I am trying to wrap my head around a concept and I am having some trouble. If I ping 8.8.8.8, 10.8.1.1 replies to me "Destination port unreachable".
Ping uses ICMP, so it does not have a '...
- 11
0
votes
2
answers
128
views
If ICMP packet is lost then another ICMP could be generated?
Suppose there are two routers between Source and destination R1, R2 respectively. Suppose source sending packet to R1 and then R1 send to R2, but R2's buffer is full and discarded the packet and ...
- 398
0
votes
1
answer
38
views
Actually ICMP message makes layer3 reliable?
We know that ICMP is connectionless because it does not require hosts to handshake before establishing a connection.
But when packets gets dropped in between route then respective router informs the ...
- 398