Tagged Questions

Abreviation of Internet Control Message Protocol. The protocol allows for the return propagation of error messages related to IP packets. ICMP is critical to basic network tools like ping and traceroute.

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outbound ICMP allow or not [duplicate]

What is you opionion to allow outbound ICMP from the networks?? I saw many opionios on this.. on one hand is usefull troubleshooting tool on other hand many DOS attacks are based on ICMP not speaking ...
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1answer
393 views

Block Packets in snort

In rules Configuration of snort , this is allowed: alert tcp any any -> any any (msg:"HTTP Connection"; react:block;) however when i write this is allowed: alert icmp any any -> any any (msg:"HTTP ...
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2k views

Computer sending unstopped ICMP echo request to an IP

I noticed while hanging in Microsoft Network Monitor that my computer is sending ICMP echo request to an arbitrary IP address 202.39.253.11. I looked for the owner of this IP and I found it is owned ...
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1answer
137 views

Why is ICMP timestamping disabled on OS X?

It would seem like ICMP timestamping is quite a useful feature for troubleshooting networks with asymmetric paths. Replies to icmp(4) timestamp requests are generated by the kernel: On OpenBSD, the ...
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1answer
286 views

Disabling Ping/ICMP Requests [duplicate]

Are there any benefits from disabling Ping/ICMP requests on servers? I've read where people say to do it but I can't seem to find any real benefits with it. Only more likely to cause more problems. ...
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1answer
2k views

Wireshark Gratuitous ARP

I'm playing around with scapy and wireshark and I have sent a packet to a destination that does not exist (10.0.2.14). Wireshark shows an ARP attempt to resolve the address but as its not there the ...
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1answer
329 views

how to handle error reply messages?

For security reasons, many organizations do not allow error reply messages to leave their internal Internets. How, specifically, could hackers use information in echo reply messages to learn about the ...
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2answers
26k views

Is it a bad idea for a firewall to block ICMP?

This question was inspired by this answer which states in part: The generic firewall manifest file finishes off by dropping everything I didn't otherwise allow (besides ICMP. Don't turn off ICMP). ...
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2answers
177 views

IP attack by reading/writing data?

If I remember correctly there is an ICMP attack whereby you can embed malicious code and it gets read/executed, causing the problem (similar to SQL injection). Are there any further/more dangerous ...
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3answers
2k views

Is there any risk in allowing ping packets *out* through a firewall

The company I'm currently doing work for does not allow ping requests out through their firewall, for "security reasons" and I'm baffled as to why this is a concern. Before you point me to (e.g.) ...
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0answers
212 views

AD authentication with high amount of ICMP traffic [closed]

We have an IPS in place and it's constantly triggering ICMP / Ping flood signatures between workstations and AD server; or AD to workstation. I understand that ICMP is used for AD authentication. ...
0
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1answer
250 views

Differentiate normal flow and broadcast attacks

How do you identify whether a broadcast traffic is normal or is considered an attack such as a DoS attack?, There is some information that the plot or the source that allows me to differentiate ...
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2answers
746 views

ICMP redirects and source routing in the wild?

Theoretically, ICMP redirect messages (IPv4 and IPv6) and source routing (IPv4) / routing headers (IPv6) are very dangerous. However, I'm curious as to if attacks using these features really work in ...
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5answers
16k views

Security risk of PING?

I have been told that PING presents a security risk, and it's a good idea to disable/block it on production web servers. Some research tells me that there are indeed security risks. Is it common ...