Hi there,

 

i just want to report two partially successfull DoS Attacks on my Relay: 

 

First attack:

 

Occured yesterday. The tor process showed massive traffic, much more my
upload ( 45 Mbits) could handle.

 

I don't know how in detail this worked, but I had receiving traffic at about
40Mbits and the relay tried to send about 100Mbits towards WAN.

 

Because I didn't know if this was harmful traffic for the tor network, I
finally pulled the plug and obtained a new IP after about 4 hours into the
attack.

 

I had the feeling that a short time, there was still unusual
sending/recieving ratio, but all related to tor.exe and it stabilized soon
after.

 

My Guess ist hat a malformed packet was sent by tor, resulting in
uncontrolled, unknown traffic to the WAN-Side.

 

The Realy had 3 DDoS Circuits killed, rejected circuits and introduce 2 at
unnormal high rate, also like 117 marked addresses. It sent about 250GB more
then it recieved.

 

The attack is also clearly visible in Tor Metrics, a massive spike in
written Bytes can be seen. 

 

Fingerprint: 8AFE4E6F05234B0184327C052B09F10191EAFAF3

 

Second Attack (today):

 

Today at about 2 p.m., the memory of the relay spiked to maximum (8GB) and
additionally 22GB of virtual memory was used.

 

This caused the process to die, with an out-of-memory Error.

 

This also must came from a malformed packet in tor.

 

Is there any known method to circumvent both of these Issues?

 

In the first event, i don't know if the error could have cleared self after
some more hours.

 

Regarding the memory issue, i think this must be resolved in the tor
software itself, allthough I thought about adding 64GB of RAM and 256GB
Page-File, just to see if it makes any difference in case of attacks.

 

But I don't think so.

 

Best regards,

 

Joker

 

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