FastPass

1
FastPass

• Status Update
• George Nychis, Priya Sankanalgram, Gaurang
  Sardesai

2
Outline

• Motivation Reminder
• Overview
• What We Have Done
• What We Want To Have Done
• Schedule
• Questions

3
Motivation / Components

• Why does FastPass exist?
• Thwart bandwidth flooding attacks
• What is the legitimate traffic?
• Can we filter the illegitimate traffic?
• How does it accomplish this?
• Tokens
• Capabilities
• Monitoring

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Design Components

• Capabilities
• Prioritize traffic end hosts agree is legitimate
• Tokens
• Ensure capability setup packet is not DoSed
• Monitoring
• No duplicate tokens
• Everyone adheres to original agreed rates

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3
int fast_path0 // Capabilities if(cap_header(pa
cket)) if(valid_hash(curr_cap))
fast_path1 insert_hash(packet) //
Tokens Monitoring if(token_header(packet))
if(token_valid(token)) fast_path1
bloom_filter_add(token) //
Monitoring if(prob_sample(packet))
take_sample(packet) check_rate(packet) HA
SH(src,dst,rate)
_at_
H1


2




2


2
3

_at_


2
3






H2



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3
int fast_path0 // Capabilities if(cap_header(pa
cket)) if(valid_hash(curr_cap))
fast_path1 insert_hash(packet) //
Tokens Monitoring if(token_header(packet))
if(token_valid(token)) fast_path1
bloom_filter_add(token) //
Monitoring if(prob_sample(packet))
take_sample(packet) check_rate(packet) HA
SH(src,dst,rate)
_at_
H1







_at_



H2
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What We Have Done

• Capabilities
• Extract header
• Compute new hash
• Check old hash with new
• Insert new hash into header
• Tokens
• Extract token
• Compute hash on token header
• Pass token to bloom filters
• Monitoring
• K number Bloom filter memory allocations
• Receive tokens
• Hash the tokens
• Loop through the K filters

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What Needs Done

• A timer!
• Cycle router private keys for capabilities
• Clear out current bloom filter and rotate them
• Indexing into bloom filter based on hash
• Checking bit values
• Flip bits of new tokens
• Woops two paths ?
• Fast Path Slow Path
• Should be easy, plenty of sample code
• Evaluation!
• Its our overall goal for FastPass

9
Schedule
10

• Questions?