Re: [Dots] WGLC for draft-dots-use-cases-19

["Konda, Tirumaleswar Reddy" <[e-mail]>]

> -----Original Message-----
> From: [e-mail]
> <[e-mail]>
> Sent: Tuesday, August 6, 2019 6:23 PM
> To: Konda, Tirumaleswar Reddy
> <[e-mail]>; Valery Smyslov
> <[e-mail]>; [e-mail]
> Cc: Xialiang (Frank, Network Standard & Patent Dept)
> <[e-mail]>
> Subject: RE: [Dots] WGLC for draft-dots-use-cases-19
> 
> This email originated from outside of the organization. Do not click links or
> open attachments unless you recognize the sender and know the content is
> safe.
> 
> Re-,
> 
> Please see inline.
> 
> Cheers,
> Med
> 
> > -----Message d'origine-----
> > De : Konda, Tirumaleswar Reddy
> > [mailto:[e-mail]]
> > Envoyé : mardi 6 août 2019 14:31
> > À : BOUCADAIR Mohamed TGI/OLN; Valery Smyslov; [e-mail] Cc :
> > Xialiang (Frank, Network Standard & Patent Dept) Objet : RE: [Dots]
> > WGLC for draft-dots-use-cases-19
> >
> > > -----Original Message-----
> > > From: [e-mail]
> > > <[e-mail]>
> > > Sent: Tuesday, August 6, 2019 5:46 PM
> > > To: Konda, Tirumaleswar Reddy
> > > <[e-mail]>; Valery Smyslov
> > > <[e-mail]>; [e-mail]
> > > Cc: Xialiang (Frank, Network Standard & Patent Dept)
> > > <[e-mail]>
> > > Subject: RE: [Dots] WGLC for draft-dots-use-cases-19
> > >
> > >
> > >
> > > Re-,
> > >
> > > Please see inline.
> > >
> > > Cheers,
> > > Med
> > >
> > > > -----Message d'origine-----
> > > > De : Konda, Tirumaleswar Reddy
> > > > [mailto:[e-mail]]
> > > > Envoyé : mardi 6 août 2019 13:52
> > > > À : BOUCADAIR Mohamed TGI/OLN; Valery Smyslov; [e-mail] Cc :
> > > > Xialiang (Frank, Network Standard & Patent Dept) Objet : RE:
> > > > [Dots] WGLC for draft-dots-use-cases-19
> > > >
> > > > > -----Original Message-----
> > > > > From: [e-mail]
> > > > > <[e-mail]>
> > > > > Sent: Tuesday, August 6, 2019 3:15 PM
> > > > > To: Konda, Tirumaleswar Reddy
> > > > > <[e-mail]>; Valery Smyslov
> > > > > <[e-mail]>; [e-mail]
> > > > > Cc: Xialiang (Frank, Network Standard & Patent Dept)
> > > > > <[e-mail]>
> > > > > Subject: RE: [Dots] WGLC for draft-dots-use-cases-19
> > > > >
> > > > >
> > > > >
> > > > > Re-,
> > > > >
> > > > > Please see inline.
> > > > >
> > > > > Cheers,
> > > > > Med
> > > > >
> > > > > > -----Message d'origine-----
> > > > > > De : Konda, Tirumaleswar Reddy
> > > > > > [mailto:[e-mail]]
> > > > > > Envoyé : mardi 6 août 2019 11:29 À : BOUCADAIR Mohamed
> > > > > > TGI/OLN; Valery Smyslov; [e-mail] Cc :
> > > > > > Xialiang (Frank, Network Standard & Patent Dept) Objet : RE:
> > > > > > [Dots] WGLC for draft-dots-use-cases-19
> > > > > >
> > > > > > > -----Original Message-----
> > > > > > > From: [e-mail]
> > > > > > > <[e-mail]>
> > > > > > > Sent: Tuesday, August 6, 2019 2:50 PM
> > > > > > > To: Konda, Tirumaleswar Reddy
> > > > > > > <[e-mail]>; Valery Smyslov
> > > > > > > <[e-mail]>; [e-mail]
> > > > > > > Cc: Xialiang (Frank, Network Standard & Patent Dept)
> > > > > > > <[e-mail]>
> > > > > > > Subject: RE: [Dots] WGLC for draft-dots-use-cases-19
> > > > > > >
> > > > > > > This email originated from outside of the organization. Do
> > > > > > > not click
> > > > > > links or
> > > > > > > open attachments unless you recognize the sender and know
> > > > > > > the content is safe.
> > > > > > >
> > > > > > > Re-,
> > > > > > >
> > > > > > > Please see inline.
> > > > > > >
> > > > > > > Cheers,
> > > > > > > Med
> > > > > > >
> > > > > > > > -----Message d'origine----- De : Konda, Tirumaleswar Reddy
> > > > > > > > [mailto:[e-mail]]
> > > > > > > > Envoyé : mardi 6 août 2019 11:15 À : BOUCADAIR Mohamed
> > > > > > > > TGI/OLN; Valery Smyslov; [e-mail] Cc :
> > > > > > > > Xialiang (Frank, Network Standard & Patent Dept) Objet : RE:
> > > > > > > > [Dots] WGLC for draft-dots-use-cases-19
> > > > > > > >
> > > > > > > > > -----Original Message-----
> > > > > > > > > From: [e-mail]
> > > > > > > > > <[e-mail]>
> > > > > > > > > Sent: Tuesday, August 6, 2019 2:00 PM
> > > > > > > > > To: Konda, Tirumaleswar Reddy
> > > > > > > > > <[e-mail]>; Valery Smyslov
> > > > > > > > > <[e-mail]>; [e-mail]
> > > > > > > > > Cc: Xialiang (Frank, Network Standard & Patent Dept)
> > > > > > > > > <[e-mail]>
> > > > > > > > > Subject: RE: [Dots] WGLC for draft-dots-use-cases-19
> > > > > > > > >
> > > > > > > > > This email originated from outside of the organization.
> > > > > > > > > Do not click
> > > > > > > > links or
> > > > > > > > > open attachments unless you recognize the sender and
> > > > > > > > > know the content is safe.
> > > > > > > > >
> > > > > > > > > Re-,
> > > > > > > > >
> > > > > > > > > Please see inline.
> > > > > > > > >
> > > > > > > > > Cheers,
> > > > > > > > > Med
> > > > > > > > >
> > > > > > > > > > -----Message d'origine----- De : Konda, Tirumaleswar
> > > > > > > > > > Reddy [mailto:[e-mail]]
> > > > > > > > > > Envoyé : mardi 6 août 2019 10:14 À : BOUCADAIR Mohamed
> > > > > > > > > > TGI/OLN; Valery Smyslov; [e-mail] Cc :
> > > > > > > > > > Xialiang (Frank, Network Standard & Patent Dept) Objet :
> > RE:
> > > > > > > > > > [Dots] WGLC for draft-dots-use-cases-19
> > > > > > > > > >
> > > > > > > > > > Hi Med,
> > > > > > > > > >
> > > > > > > > > > No, the orchestrator is not ignoring the mitigation hints.
> > > > > > > > >
> > > > > > > > > [Med] Why? The text is clear the orchestrator acts as
> > > > > > > > > DOTS
> > > > server.
> > > > > > > > > As
> > > > > > > > such, it
> > > > > > > > > can ignore/accept hints.
> > > > > > > > >
> > > > > > > > >  It is sending
> > > > > > > > > > filtering rules to block or rate-limit traffic to
> > > > > > > > > > routers (last but one line in the new paragraph).
> > > > > > > > >
> > > > > > > > > [Med] Yes. That filtering rule is that would be applied
> > > > > > > > > by the DMS if it
> > > > > > > > has
> > > > > > > > > sufficient resources.
> > > > > > > > >
> > > > > > > > >  The adverse impact is legitimate users whose
> > > > > > > > > > IP addresses were spoofed cannot access the services
> > > > > > > > > > of the target server.
> > > > > > > > >
> > > > > > > > > [Med] This is a check at the DMS side. This check
> > > > > > > > > applies independently
> > > > > > > > of **
> > > > > > > > > where ** the filters are applied. This is not specific
> > > > > > > > > to this NEW
> > > > > > text.
> > > > > > > >
> > > > > > > > If the orchestrator is sending filtering rules to block
> > > > > > > > traffic, checks are required to ensure spoofed IP address
> > > > > > > > are not conveyed by
> > > > > > the
> > > > > > > DMS.
> > > > > > >
> > > > > > > [Med] Yes, but the current text describes the case where the
> > > > > > > DMS
> > > > > > supplies
> > > > > > > "its blocked traffic information":
> > > > > > >
> > > > > > >   the DDoS mitigation system can send mitigation requests
> > > > > > >   with additional hints such as its blocked traffic
> > > > > > > information to
> > > > the
> > > > > > >                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > > > > >   orchestrator.
> > > > > > >
> > > > > > > So, the DMS has already done that check.
> > > > > >
> > > > > > The blocked traffic information will include attack traffic
> > > > > > from both spoofed and attacker IP addresses.
> > > > > >
> > > > >
> > > > > [Med] If you are saying that there is an issue if the DMS does
> > > > > not
> > > > check, you
> > > > > are right. But, again, this is not specific to the NEW text.
> > > > > This is a
> > > > general
> > > > > problem (that is outside DOTS, BTW).
> > > >
> > > > No, DMS will anyway check and try not block legitimate traffic
> > > > from users whose IP addresses have been spoofed.
> > > >
> > >
> > > [Med] What I'm saying is that the DMS will then follow the same
> > > logic
> > when
> > > providing the hints to the orchestrator.
> >
> > No, the hints should include both spoofed and non-spoofed IP addresses
> > used to attack the target.
> >
> 
> [Med] Why? A DMS may decide to offload only filtering rules its checked.
> 
> Even if we assume that the check is at the orchestrator side, this is not a new
> threat vector.
> 
> > >
> > > > >
> > > > >
> > > > > > >
> > > > > > >  If
> > > > > > > > the orchestrator delegates the mitigation to a separate
> > > > > > > > domain (recursive signaling), the attack information
> > > > > > > > provided by DMS can include spoofed IP addresses (so the
> > > > > > > > new mitigator in the separate domain learns the attack
> > > > > > > > traffic is coming from spoofed IP
> > > > addresses).
> > > > > > >
> > > > > > > [Med] This is not specific to this case, but applies each
> > > > > > > time there is
> > > > > > recursive
> > > > > > > signaling.
> > > > > >
> > > > > > My comment is to using the attack information of spoofed IP
> > > > > > addresses to filter traffic would penalize legitimate users,
> > > > > > and the text is not clear me. I suggest adding a line for
> > > > > > clarity, DMS may supply both spoofed and attacker IP addresses
> > > > > > in the attack information to the orchestrator. The
> > > > > > orchestrator will only use the non-spoofed IP addresses to
> > > > > > enforce filtering rules on
> > routers.
> > > > >
> > > > > [Med] I was assuming this is already done by the DMS to generate
> > > > > "its blocked traffic information", but if you prefer the text to
> > > > > be explicit,
> > > > it will
> > > > > need to be generic:
> > > > >
> > > > > the check is not specific to the NEW text but applies also in
> > > > > the
> > > > general DMS
> > > > > case (without offloading).
> > > >
> > > > When DMS generates the attack traffic information it should
> > > > include both spoofed and attacker IP addresses (tagged with
> > > > whether the IP address is spoofed or not).
> > >
> > > [Med] Why it should not check?
> >
> > It checks and includes both type of IP addresses.
> 
> [Med] Why it has to include both if it has done the check?
> 
> >
> > >
> > > If the orchestrator is delegating the mitigation to a
> > > > separate domain, it can propagate the attack information so the
> > > > mitigator in the separate domain has knowledge that the attacker
> > > > is using spoofed IP addresses and the mitigator can optionally use
> > > > the attack information to determine the mitigation strategy.
> > >
> > > [Med] The recursive case is not covered in the current text. I don't
> > think we
> > > need to elaborate on this further.
> >
> > I don't understand why recursive case should be excluded in the
> > current text ?
> 
> [Med] Because the use-case draft does not cover this: It only covers the case
> of an orchestrator talking to local routers.

My question is why shouldn't the use case draft cover this ?

> 
> >
> > >
> > >  However If orchestrator is enforcing
> > > > filtering rules on routers, it should create the black-list rules
> > > > based on the non-spoofed attacker IP address and not use the
> > > > spoofed victim IP addresses.
> > > >
> > >
> > > [Med] Agree. Whether the check is done at the orchestrator or by the
> > DMS,
> > > is not a new concern. The DMS has to proceed with these checks, anyway.
> > I
> > > fail to see what is NEW and SPECIFIC to the offload scenario.
> >
> > In this case the check has to be done by orchestrator when enforcing
> > black-list rules not to penalize the spoofed victim IP addresses and
> > should be discussed in the new use case.
> 
> [Med] This requirement has to be followed by the DMS, anyway. This is not a
> new issue, Tiru.

No, sending attack information to the DOTS server is not covered in any of the WG documents.

> 
>  I don't see any other use case in
> > the specification discussing offload scenario with propagating the
> > attack information and I recommend updating the text discussing the
> > above scenarios.
> 
> [Med] We don't have a similar text for the DMS case because mitigation is
> out of scope. I'm expecting to follow the some rationale for the offload.

If mitigation is out of scope, remove the following line:
Then the orchestrator can take further actions like requesting forwarding nodes such as routers to filter the traffic.

-Tiru

> 
> >
> > Cheers,
> > -Tiru