Re: [j-nsp] Flowspec not filtering traffic.
Hi Nitzan, This is a custom policy to catch Carpet Bomb attacks ( low traffic to each /32 host from a larger network /22 for example). But we are getting the same results ( no flow spec filtering) on any port, like 123 , 53 , and every amplification type attack. Em ter., 20 de set. de 2022 às 16:56, Nitzan Tzelniker < nitzan.tzelni...@gmail.com> escreveu: > BTW, > > As I see Kentik in the name of the BGP group > The default Kentik DDoS policie "UDP Fragments Attack" match udp port 0 > and the flowspec rule attached to it match is-fragment and first-fragment > So I don't understand why it send filter that match udp port 0 ? > Did you change the default one ? > > Nitzan > > On Sun, Sep 18, 2022 at 10:06 PM Gustavo Santos via juniper-nsp < > juniper-nsp@puck.nether.net> wrote: > >> Hi Alexandre, >> >> The detection system throws for example port 123 and port 0 rules at the >> same time. >> >> But I got the logic but for example on our flow monitoring system we got >> 30Gbps of udp flood towards a customer, 25Gbps are from source port 123 >> and >> 5gbps are from port 0. >> >> What we get here is that All of the traffic is forwarded to the customer ( >> 30gbps) instead of being filtered or not being forwarded to the customer´s >> interface. >> >> I think I can set the detection system to change its behavior from port 0 >> to udp fragment. >> >> Thanks for your input. >> >> Em dom., 18 de set. de 2022 às 14:25, Alexandre Snarskii < >> s...@snar.spb.ru> >> escreveu: >> >> > On Sat, Sep 17, 2022 at 11:41:58AM -0300, Gustavo Santos via juniper-nsp >> > wrote: >> > > Hi Saku, >> > > >> > > PS: Real ASN was changed to 65000 on the configuration snippet. >> > > >> > > >> > > >> > > show route table inetflow.0 extensive >> > > >> > > 1x8.2x8.84.34,*,proto=17,port=0/term:7 (1 entry, 1 announced) >> > >> > port=0 seems to be poor choice when trying to shut down NTP reflection, >> > with this rule your router filters only small fraction of DDoS traffic.. >> > >> > Background: >> > - udp reflection attacks try go generate as much traffic as possible, >> > so, amplification attacks usually carry lots of fragmented traffic. >> > - when non-first fragment enters your router it does not contain >> > UDP header so it's reported by netflow as having source and destination >> > ports of zeros. >> > - your detection system generates and injects flowspec matching port=0, >> > - now when your router sees first fragment of amplified packet, it does >> > not matches this rule (source port is 123 and destination port is >> usually >> > non-zero too), so your router passes this packet. >> > - when your router sees non-first fragment of amplified packet, >> > it understand that it does not know neither source nor destination >> > ports, so it can't compare against this rule, so this packet is >> > not matched and passed too. >> > - so, what is filtered is only these (rare) packets that are the >> > first fragments and have destination port of zero. >> > >> > What you can try here: replace port matching with is-fragment matching. >> > In JunOS syntax it will be >> > >> > set routing-options flow route NTP-AMP match destination >> 1x8.2x8.84.34/32 >> > set routing-options flow route NTP-AMP match protocol udp fragment >> > is-fragment >> > set routing-options flow route NTP-AMP then discard >> > >> > > TSI: >> > > KRT in dfwd; >> > > Action(s): discard,count >> > > Page 0 idx 0, (group KENTIK_FS type Internal) Type 1 val 0x63b7c098 >> > > (adv_entry) >> > >Advertised metrics: >> > > Flags: NoNexthop >> > > Localpref: 100 >> > > AS path: [65000 I >> > > Communities: traffic-rate:52873:0 >> > > Advertise: 0001 >> > > Path 1x8.2x8.84.34,*,proto=17,port=0 >> > > Vector len 4. Val: 0 >> > > *Flow Preference: 5 >> > > Next hop type: Fictitious, Next hop index: 0 >> > > Address: 0x5214bfc >> > > Next-hop reference count: 22 >> > > Next hop: >> > > State: >> > > Local AS: 52873 >> > > Age: 8w0d 20:30:33 >> > > Validation State: unverified >> > > Task: RT Flow >> > > Announcement bits (2): 0-Flow 1-BGP_RT_Background >> > > AS path: I >> > > Communities: traffic-rate:65000:0 >> > > >> > > show firewall >> > > >> > > Filter: __flowspec_default_inet__ >> > > Counters: >> > > NameBytes >> > > Packets >> > > 1x8.2x8.84.34,*,proto=17,port=0 19897391083 >> > > 510189535 >> > > >> > > >> > > BGP Group >> > > >> > > {master}[edit protocols bgp group KENTIK_FS] >> > > type internal; >> > > hold-time 720; >> > > mtu-discovery; >> > > family inet { >> > > unicast; >> > > flow { >> > > no-validate flowspec-import; >> > > } >> > > } >> > > } >> > > >> > > >> > > >> > > Import policy >> > > {master}[edit] >> > > gustavo@MX10K3#
Re: [j-nsp] Flowspec not filtering traffic.
BTW, As I see Kentik in the name of the BGP group The default Kentik DDoS policie "UDP Fragments Attack" match udp port 0 and the flowspec rule attached to it match is-fragment and first-fragment So I don't understand why it send filter that match udp port 0 ? Did you change the default one ? Nitzan On Sun, Sep 18, 2022 at 10:06 PM Gustavo Santos via juniper-nsp < juniper-nsp@puck.nether.net> wrote: > Hi Alexandre, > > The detection system throws for example port 123 and port 0 rules at the > same time. > > But I got the logic but for example on our flow monitoring system we got > 30Gbps of udp flood towards a customer, 25Gbps are from source port 123 and > 5gbps are from port 0. > > What we get here is that All of the traffic is forwarded to the customer ( > 30gbps) instead of being filtered or not being forwarded to the customer´s > interface. > > I think I can set the detection system to change its behavior from port 0 > to udp fragment. > > Thanks for your input. > > Em dom., 18 de set. de 2022 às 14:25, Alexandre Snarskii > > escreveu: > > > On Sat, Sep 17, 2022 at 11:41:58AM -0300, Gustavo Santos via juniper-nsp > > wrote: > > > Hi Saku, > > > > > > PS: Real ASN was changed to 65000 on the configuration snippet. > > > > > > > > > > > > show route table inetflow.0 extensive > > > > > > 1x8.2x8.84.34,*,proto=17,port=0/term:7 (1 entry, 1 announced) > > > > port=0 seems to be poor choice when trying to shut down NTP reflection, > > with this rule your router filters only small fraction of DDoS traffic.. > > > > Background: > > - udp reflection attacks try go generate as much traffic as possible, > > so, amplification attacks usually carry lots of fragmented traffic. > > - when non-first fragment enters your router it does not contain > > UDP header so it's reported by netflow as having source and destination > > ports of zeros. > > - your detection system generates and injects flowspec matching port=0, > > - now when your router sees first fragment of amplified packet, it does > > not matches this rule (source port is 123 and destination port is usually > > non-zero too), so your router passes this packet. > > - when your router sees non-first fragment of amplified packet, > > it understand that it does not know neither source nor destination > > ports, so it can't compare against this rule, so this packet is > > not matched and passed too. > > - so, what is filtered is only these (rare) packets that are the > > first fragments and have destination port of zero. > > > > What you can try here: replace port matching with is-fragment matching. > > In JunOS syntax it will be > > > > set routing-options flow route NTP-AMP match destination 1x8.2x8.84.34/32 > > set routing-options flow route NTP-AMP match protocol udp fragment > > is-fragment > > set routing-options flow route NTP-AMP then discard > > > > > TSI: > > > KRT in dfwd; > > > Action(s): discard,count > > > Page 0 idx 0, (group KENTIK_FS type Internal) Type 1 val 0x63b7c098 > > > (adv_entry) > > >Advertised metrics: > > > Flags: NoNexthop > > > Localpref: 100 > > > AS path: [65000 I > > > Communities: traffic-rate:52873:0 > > > Advertise: 0001 > > > Path 1x8.2x8.84.34,*,proto=17,port=0 > > > Vector len 4. Val: 0 > > > *Flow Preference: 5 > > > Next hop type: Fictitious, Next hop index: 0 > > > Address: 0x5214bfc > > > Next-hop reference count: 22 > > > Next hop: > > > State: > > > Local AS: 52873 > > > Age: 8w0d 20:30:33 > > > Validation State: unverified > > > Task: RT Flow > > > Announcement bits (2): 0-Flow 1-BGP_RT_Background > > > AS path: I > > > Communities: traffic-rate:65000:0 > > > > > > show firewall > > > > > > Filter: __flowspec_default_inet__ > > > Counters: > > > NameBytes > > > Packets > > > 1x8.2x8.84.34,*,proto=17,port=0 19897391083 > > > 510189535 > > > > > > > > > BGP Group > > > > > > {master}[edit protocols bgp group KENTIK_FS] > > > type internal; > > > hold-time 720; > > > mtu-discovery; > > > family inet { > > > unicast; > > > flow { > > > no-validate flowspec-import; > > > } > > > } > > > } > > > > > > > > > > > > Import policy > > > {master}[edit] > > > gustavo@MX10K3# edit policy-options policy-statement flowspec-import > > > > > > {master}[edit policy-options policy-statement flowspec-import] > > > gustavo@MX10K3# show > > > term 1 { > > > then accept; > > > } > > > > > > IP transit interface > > > > > > {master}[edit interfaces ae0 unit 10] > > > gustavo@MX10K3# show > > > vlan-id 10; > > > family inet { > > > mtu 1500; > > > filter { > > > inactive: input ddos; > > > } > > > sampling { > > > input; > > > } > > > address x.x.x.x.x/31; > > > } > > >
Re: [j-nsp] Flowspec not filtering traffic.
I can't blame the port=0, even though I agree with the explanation that you shouldn't rely on it for identifying fragmentation. Looking at the program, whenever the counter you mentioned (1x8.2x8.84.34,*,proto=17,port=0) is punched, it is also discarded. And you can observe the counter being punched, therefore it should be discarded to my understanding of the PFE programming. The first term surprises me a little bit. It basically seems to be 'if interface-group is 0 or 2-255 permit, otherwise check next term', but it doesn't seem to offer any help to you, just curious detail. Unless the help is, the counter and discard are working as intended, it's just the interface you are interested in, belongs to interface-group 1, and traffic from that interface is not being filtered. For the next step, I would reduce the complexity of your test to single term, with just src or dst IP address match of some test address, and review. On Sun, 18 Sept 2022 at 22:05, Gustavo Santos wrote: > > Hi Alexandre, > > The detection system throws for example port 123 and port 0 rules at the > same time. > > But I got the logic but for example on our flow monitoring system we got > 30Gbps of udp flood towards a customer, 25Gbps are from source port 123 and > 5gbps are from port 0. > > What we get here is that All of the traffic is forwarded to the customer ( > 30gbps) instead of being filtered or not being forwarded to the customer´s > interface. > > I think I can set the detection system to change its behavior from port 0 to > udp fragment. > > Thanks for your input. > > Em dom., 18 de set. de 2022 às 14:25, Alexandre Snarskii > escreveu: >> >> On Sat, Sep 17, 2022 at 11:41:58AM -0300, Gustavo Santos via juniper-nsp >> wrote: >> > Hi Saku, >> > >> > PS: Real ASN was changed to 65000 on the configuration snippet. >> > >> > >> > >> > show route table inetflow.0 extensive >> > >> > 1x8.2x8.84.34,*,proto=17,port=0/term:7 (1 entry, 1 announced) >> >> port=0 seems to be poor choice when trying to shut down NTP reflection, >> with this rule your router filters only small fraction of DDoS traffic.. >> >> Background: >> - udp reflection attacks try go generate as much traffic as possible, >> so, amplification attacks usually carry lots of fragmented traffic. >> - when non-first fragment enters your router it does not contain >> UDP header so it's reported by netflow as having source and destination >> ports of zeros. >> - your detection system generates and injects flowspec matching port=0, >> - now when your router sees first fragment of amplified packet, it does >> not matches this rule (source port is 123 and destination port is usually >> non-zero too), so your router passes this packet. >> - when your router sees non-first fragment of amplified packet, >> it understand that it does not know neither source nor destination >> ports, so it can't compare against this rule, so this packet is >> not matched and passed too. >> - so, what is filtered is only these (rare) packets that are the >> first fragments and have destination port of zero. >> >> What you can try here: replace port matching with is-fragment matching. >> In JunOS syntax it will be >> >> set routing-options flow route NTP-AMP match destination 1x8.2x8.84.34/32 >> set routing-options flow route NTP-AMP match protocol udp fragment >> is-fragment >> set routing-options flow route NTP-AMP then discard >> >> > TSI: >> > KRT in dfwd; >> > Action(s): discard,count >> > Page 0 idx 0, (group KENTIK_FS type Internal) Type 1 val 0x63b7c098 >> > (adv_entry) >> >Advertised metrics: >> > Flags: NoNexthop >> > Localpref: 100 >> > AS path: [65000 I >> > Communities: traffic-rate:52873:0 >> > Advertise: 0001 >> > Path 1x8.2x8.84.34,*,proto=17,port=0 >> > Vector len 4. Val: 0 >> > *Flow Preference: 5 >> > Next hop type: Fictitious, Next hop index: 0 >> > Address: 0x5214bfc >> > Next-hop reference count: 22 >> > Next hop: >> > State: >> > Local AS: 52873 >> > Age: 8w0d 20:30:33 >> > Validation State: unverified >> > Task: RT Flow >> > Announcement bits (2): 0-Flow 1-BGP_RT_Background >> > AS path: I >> > Communities: traffic-rate:65000:0 >> > >> > show firewall >> > >> > Filter: __flowspec_default_inet__ >> > Counters: >> > NameBytes >> > Packets >> > 1x8.2x8.84.34,*,proto=17,port=0 19897391083 >> > 510189535 >> > >> > >> > BGP Group >> > >> > {master}[edit protocols bgp group KENTIK_FS] >> > type internal; >> > hold-time 720; >> > mtu-discovery; >> > family inet { >> > unicast; >> > flow { >> > no-validate flowspec-import; >> > } >> > } >> > } >> > >> > >> > >> > Import policy >> > {master}[edit] >> > gustavo@MX10K3# edit policy-options policy-statement
Re: [j-nsp] Flowspec not filtering traffic.
Hi Alexandre, The detection system throws for example port 123 and port 0 rules at the same time. But I got the logic but for example on our flow monitoring system we got 30Gbps of udp flood towards a customer, 25Gbps are from source port 123 and 5gbps are from port 0. What we get here is that All of the traffic is forwarded to the customer ( 30gbps) instead of being filtered or not being forwarded to the customer´s interface. I think I can set the detection system to change its behavior from port 0 to udp fragment. Thanks for your input. Em dom., 18 de set. de 2022 às 14:25, Alexandre Snarskii escreveu: > On Sat, Sep 17, 2022 at 11:41:58AM -0300, Gustavo Santos via juniper-nsp > wrote: > > Hi Saku, > > > > PS: Real ASN was changed to 65000 on the configuration snippet. > > > > > > > > show route table inetflow.0 extensive > > > > 1x8.2x8.84.34,*,proto=17,port=0/term:7 (1 entry, 1 announced) > > port=0 seems to be poor choice when trying to shut down NTP reflection, > with this rule your router filters only small fraction of DDoS traffic.. > > Background: > - udp reflection attacks try go generate as much traffic as possible, > so, amplification attacks usually carry lots of fragmented traffic. > - when non-first fragment enters your router it does not contain > UDP header so it's reported by netflow as having source and destination > ports of zeros. > - your detection system generates and injects flowspec matching port=0, > - now when your router sees first fragment of amplified packet, it does > not matches this rule (source port is 123 and destination port is usually > non-zero too), so your router passes this packet. > - when your router sees non-first fragment of amplified packet, > it understand that it does not know neither source nor destination > ports, so it can't compare against this rule, so this packet is > not matched and passed too. > - so, what is filtered is only these (rare) packets that are the > first fragments and have destination port of zero. > > What you can try here: replace port matching with is-fragment matching. > In JunOS syntax it will be > > set routing-options flow route NTP-AMP match destination 1x8.2x8.84.34/32 > set routing-options flow route NTP-AMP match protocol udp fragment > is-fragment > set routing-options flow route NTP-AMP then discard > > > TSI: > > KRT in dfwd; > > Action(s): discard,count > > Page 0 idx 0, (group KENTIK_FS type Internal) Type 1 val 0x63b7c098 > > (adv_entry) > >Advertised metrics: > > Flags: NoNexthop > > Localpref: 100 > > AS path: [65000 I > > Communities: traffic-rate:52873:0 > > Advertise: 0001 > > Path 1x8.2x8.84.34,*,proto=17,port=0 > > Vector len 4. Val: 0 > > *Flow Preference: 5 > > Next hop type: Fictitious, Next hop index: 0 > > Address: 0x5214bfc > > Next-hop reference count: 22 > > Next hop: > > State: > > Local AS: 52873 > > Age: 8w0d 20:30:33 > > Validation State: unverified > > Task: RT Flow > > Announcement bits (2): 0-Flow 1-BGP_RT_Background > > AS path: I > > Communities: traffic-rate:65000:0 > > > > show firewall > > > > Filter: __flowspec_default_inet__ > > Counters: > > NameBytes > > Packets > > 1x8.2x8.84.34,*,proto=17,port=0 19897391083 > > 510189535 > > > > > > BGP Group > > > > {master}[edit protocols bgp group KENTIK_FS] > > type internal; > > hold-time 720; > > mtu-discovery; > > family inet { > > unicast; > > flow { > > no-validate flowspec-import; > > } > > } > > } > > > > > > > > Import policy > > {master}[edit] > > gustavo@MX10K3# edit policy-options policy-statement flowspec-import > > > > {master}[edit policy-options policy-statement flowspec-import] > > gustavo@MX10K3# show > > term 1 { > > then accept; > > } > > > > IP transit interface > > > > {master}[edit interfaces ae0 unit 10] > > gustavo@MX10K3# show > > vlan-id 10; > > family inet { > > mtu 1500; > > filter { > > inactive: input ddos; > > } > > sampling { > > input; > > } > > address x.x.x.x.x/31; > > } > > > > > > Em sáb., 17 de set. de 2022 às 03:00, Saku Ytti escreveu: > > > > > Can you provide some output. > > > > > > Like 'show route table inetflow.0 extensive' and config. > > > > > > On Sat, 17 Sept 2022 at 05:05, Gustavo Santos via juniper-nsp > > > wrote: > > > > > > > > Hi, > > > > > > > > We have noticed that flowspec is not working or filtering as > expected. > > > > Trying a DDoS detection and rule generator tool, and we noticed that > the > > > > flowspec rule is installed, > > > > the filter counter is increasing , but no filtering at all. > > > > > > > > For example DDoS traffic from source port UDP port 123 is coming > from an > > > > Internet Transit > > >
Re: [j-nsp] Flowspec not filtering traffic.
Weird, show route flow validation detail came out empty. But on PFE looks like rules are been accepted. But when DDoS traffic comes with high volume, all of them are forwarded to customers instead of being dropped at the edge.. {master} gustavo@MX10K3> show route flow validation detail inet.0: {master} show filter inside pfe ( shows only this index for flowspec) 65024 Classic- __flowspec_default_inet__ SMPC0(MX10003-CORE vty)# show filter index 65024 program Filter index = 65024 Optimization flag: 0xf7 Filter notify host id = 0 Pfe Mask = 0x jnh inst = 0x0 Filter properties: None Filter state = CONSISTENT term interface-group term priority 0 interface-group 0 2-255 true branch to match action in rule default-term false branch to match protocol in rule 4?.1?3.1?9.2?9,*,proto=1 term 4?.1?3.1?9.209,*,proto=1 term priority 0 protocol 1 6 -> port in 1?8.2?8.?4.15,*,proto=6,port=123 17 -> port in 1?8.2?8.?4.15,*,proto=17,port=123 false branch to match action in rule default-term destination-address 45.1?3.1?9.209/32 1?8.2?8.8?.4/32 -> action in 168.228.84.4,*,proto=1 1?8.2?8.8?.15/32 -> action in 168.228.84.15,*,proto=1 1?8.2?8.8?.34/32 -> action in 168.228.84.34,*,proto=1 1?8.2?8.8?.61/32 -> action in 168.228.84.61,*,proto=1 false branch to match action in rule default-term then discard count 4?.1?3.1?9.209,*,proto=1 term 1?8.2?8.8?.4,*,proto=1 term priority 0 then discard count 1?8.2?8.84.4,*,proto=1 term 1?8.2?8.84.15,*,proto=1 term priority 0 then discard count 168.228.84.15,*,proto=1 term 168.228.84.15,*,proto=6,port=123 term priority 0 port 123 false branch to match action in rule default-term destination-address 1?8.2?8.?4.15/32 false branch to match action in rule default-term then discard count 1?8.2?8.?4.15,*,proto=6,port=123 term 1?8.2?8.?4.15,*,proto=17,port=123 term priority 0 port 123 false branch to match port in rule 1?8.2?8.?4.34,*,proto=17,port=0 destination-address 1?8.2?8.34.15/32 false branch to match port in rule 1?8.2?8.84.34,*,proto=17,port=0 then discard count 1?8.2?8.84.15,*,proto=17,port=123 term 1?8.2?8.84.34,*,proto=1 term priority 0 then discard count 1?8.2?8.84.34,*,proto=1 term 1?8.2?8.84.34,*,proto=17,port=0 term priority 0 port 0 false branch to match port in rule 1?8.2?8.84.34,*,proto=17,port=123 destination-address 1?8.2?8.84.34/32 false branch to match port in rule 1?8.2?8.84.34,*,proto=17,port=123 then discard count 1?8.2?8.84.34,*,proto=17,port=0 term 1?8.2?8.84.34,*,proto=17,port=123 term priority 0 port 123 false branch to match port in rule 1?8.2?8.84.190,*,proto=17,port=9001 destination-address 1?8.2?8.84.34/32 false branch to match port in rule 1?8.2?8.84.190,*,proto=17,port=9001 then discard count 1?8.2?8.84.34,*,proto=17,port=123 term 1?8.2?8.84.61,*,proto=1 term priority 0 then discard count 1?8.2?8.84.61,*,proto=1 term 1?8.2?8.84.190,*,proto=17,port=9001 term priority 0 port 9001 false branch to match action in rule default-term destination-address 1?8.2?8.84.190/32 false branch to match action in rule default-term then discard count 1?8.2?8.84.190,*,proto=17,port=9001 term default-term term priority 0 then accept Em dom., 18 de set. de 2022 às 03:57, Saku Ytti escreveu: > Actually I think I'm confused, I'm just not accustomed to seeing other > than 0:0 as rate, but it may be thaat the first 0 doesn't matter. > > I would verify 'show route flow validation detail' as well as verify > presence of policers if any (in PFE 'show filter counters'). > > I'd also look at the filter more closely at PFE: > - show filter (get the index) > - show filter index X program > > > > On Sun, 18 Sept 2022 at 09:39, Saku Ytti wrote: > > > > Are you exceeding the configured rate for the policer? Did you expect > > to drop at any rate? The rule sets a non-0 policing rate. > > > > On Sat, 17 Sept 2022 at 17:42, Gustavo Santos > wrote: > > > > > > Hi Saku, > > > > > > PS: Real ASN was changed to 65000 on the configuration snippet. > > > > > > > > > > > > show route table inetflow.0 extensive > > > > > > 1x8.2x8.84.34,*,proto=17,port=0/term:7 (1 entry, 1 announced) > > > TSI: > > > KRT in dfwd; > > > Action(s): discard,count > > > Page 0 idx 0, (group KENTIK_FS type Internal) Type 1 val 0x63b7c098 > (adv_entry) > > >Advertised metrics: > > > Flags: NoNexthop > > > Localpref: 100 > > > AS path: [65000 I > > > Communities: traffic-rate:52873:0 > > > Advertise: 0001 > > > Path
Re: [j-nsp] Flowspec not filtering traffic.
On Sat, Sep 17, 2022 at 11:41:58AM -0300, Gustavo Santos via juniper-nsp wrote: > Hi Saku, > > PS: Real ASN was changed to 65000 on the configuration snippet. > > > > show route table inetflow.0 extensive > > 1x8.2x8.84.34,*,proto=17,port=0/term:7 (1 entry, 1 announced) port=0 seems to be poor choice when trying to shut down NTP reflection, with this rule your router filters only small fraction of DDoS traffic.. Background: - udp reflection attacks try go generate as much traffic as possible, so, amplification attacks usually carry lots of fragmented traffic. - when non-first fragment enters your router it does not contain UDP header so it's reported by netflow as having source and destination ports of zeros. - your detection system generates and injects flowspec matching port=0, - now when your router sees first fragment of amplified packet, it does not matches this rule (source port is 123 and destination port is usually non-zero too), so your router passes this packet. - when your router sees non-first fragment of amplified packet, it understand that it does not know neither source nor destination ports, so it can't compare against this rule, so this packet is not matched and passed too. - so, what is filtered is only these (rare) packets that are the first fragments and have destination port of zero. What you can try here: replace port matching with is-fragment matching. In JunOS syntax it will be set routing-options flow route NTP-AMP match destination 1x8.2x8.84.34/32 set routing-options flow route NTP-AMP match protocol udp fragment is-fragment set routing-options flow route NTP-AMP then discard > TSI: > KRT in dfwd; > Action(s): discard,count > Page 0 idx 0, (group KENTIK_FS type Internal) Type 1 val 0x63b7c098 > (adv_entry) >Advertised metrics: > Flags: NoNexthop > Localpref: 100 > AS path: [65000 I > Communities: traffic-rate:52873:0 > Advertise: 0001 > Path 1x8.2x8.84.34,*,proto=17,port=0 > Vector len 4. Val: 0 > *Flow Preference: 5 > Next hop type: Fictitious, Next hop index: 0 > Address: 0x5214bfc > Next-hop reference count: 22 > Next hop: > State: > Local AS: 52873 > Age: 8w0d 20:30:33 > Validation State: unverified > Task: RT Flow > Announcement bits (2): 0-Flow 1-BGP_RT_Background > AS path: I > Communities: traffic-rate:65000:0 > > show firewall > > Filter: __flowspec_default_inet__ > Counters: > NameBytes > Packets > 1x8.2x8.84.34,*,proto=17,port=0 19897391083 > 510189535 > > > BGP Group > > {master}[edit protocols bgp group KENTIK_FS] > type internal; > hold-time 720; > mtu-discovery; > family inet { > unicast; > flow { > no-validate flowspec-import; > } > } > } > > > > Import policy > {master}[edit] > gustavo@MX10K3# edit policy-options policy-statement flowspec-import > > {master}[edit policy-options policy-statement flowspec-import] > gustavo@MX10K3# show > term 1 { > then accept; > } > > IP transit interface > > {master}[edit interfaces ae0 unit 10] > gustavo@MX10K3# show > vlan-id 10; > family inet { > mtu 1500; > filter { > inactive: input ddos; > } > sampling { > input; > } > address x.x.x.x.x/31; > } > > > Em sáb., 17 de set. de 2022 às 03:00, Saku Ytti escreveu: > > > Can you provide some output. > > > > Like 'show route table inetflow.0 extensive' and config. > > > > On Sat, 17 Sept 2022 at 05:05, Gustavo Santos via juniper-nsp > > wrote: > > > > > > Hi, > > > > > > We have noticed that flowspec is not working or filtering as expected. > > > Trying a DDoS detection and rule generator tool, and we noticed that the > > > flowspec rule is installed, > > > the filter counter is increasing , but no filtering at all. > > > > > > For example DDoS traffic from source port UDP port 123 is coming from an > > > Internet Transit > > > facing interface AE0. > > > The destination of this traffic is to a customer Interface ET-0/0/10. > > > > > > Even with all information and "show" commands confirming that the traffic > > > has been filtered, customer and snmp and netflow from the customer facing > > > interface is showing that the "filtered" traffic is hitting the > > destination. > > > > > > Is there any caveat or limitation or anyone hit this issue? I tried this > > > with two MX10003 routers one with 19.R3-xxx and the other one with 20.4R3 > > > junos branch. > > > > > > Regards. > > > ___ > > > juniper-nsp mailing list juniper-nsp@puck.nether.net > > > https://puck.nether.net/mailman/listinfo/juniper-nsp > > > > > > > > -- > > ++ytti > > > ___ > juniper-nsp mailing list juniper-nsp@puck.nether.net >
Re: [j-nsp] Flowspec not filtering traffic.
Actually I think I'm confused, I'm just not accustomed to seeing other than 0:0 as rate, but it may be thaat the first 0 doesn't matter. I would verify 'show route flow validation detail' as well as verify presence of policers if any (in PFE 'show filter counters'). I'd also look at the filter more closely at PFE: - show filter (get the index) - show filter index X program On Sun, 18 Sept 2022 at 09:39, Saku Ytti wrote: > > Are you exceeding the configured rate for the policer? Did you expect > to drop at any rate? The rule sets a non-0 policing rate. > > On Sat, 17 Sept 2022 at 17:42, Gustavo Santos wrote: > > > > Hi Saku, > > > > PS: Real ASN was changed to 65000 on the configuration snippet. > > > > > > > > show route table inetflow.0 extensive > > > > 1x8.2x8.84.34,*,proto=17,port=0/term:7 (1 entry, 1 announced) > > TSI: > > KRT in dfwd; > > Action(s): discard,count > > Page 0 idx 0, (group KENTIK_FS type Internal) Type 1 val 0x63b7c098 > > (adv_entry) > >Advertised metrics: > > Flags: NoNexthop > > Localpref: 100 > > AS path: [65000 I > > Communities: traffic-rate:52873:0 > > Advertise: 0001 > > Path 1x8.2x8.84.34,*,proto=17,port=0 > > Vector len 4. Val: 0 > > *Flow Preference: 5 > > Next hop type: Fictitious, Next hop index: 0 > > Address: 0x5214bfc > > Next-hop reference count: 22 > > Next hop: > > State: > > Local AS: 52873 > > Age: 8w0d 20:30:33 > > Validation State: unverified > > Task: RT Flow > > Announcement bits (2): 0-Flow 1-BGP_RT_Background > > AS path: I > > Communities: traffic-rate:65000:0 > > > > show firewall > > > > Filter: __flowspec_default_inet__ > > Counters: > > NameBytes > > Packets > > 1x8.2x8.84.34,*,proto=17,port=0 19897391083 > > 510189535 > > > > > > BGP Group > > > > {master}[edit protocols bgp group KENTIK_FS] > > type internal; > > hold-time 720; > > mtu-discovery; > > family inet { > > unicast; > > flow { > > no-validate flowspec-import; > > } > > } > > } > > > > > > > > Import policy > > {master}[edit] > > gustavo@MX10K3# edit policy-options policy-statement flowspec-import > > > > {master}[edit policy-options policy-statement flowspec-import] > > gustavo@MX10K3# show > > term 1 { > > then accept; > > } > > > > IP transit interface > > > > {master}[edit interfaces ae0 unit 10] > > gustavo@MX10K3# show > > vlan-id 10; > > family inet { > > mtu 1500; > > filter { > > inactive: input ddos; > > } > > sampling { > > input; > > } > > address x.x.x.x.x/31; > > } > > > > > > Em sáb., 17 de set. de 2022 às 03:00, Saku Ytti escreveu: > >> > >> Can you provide some output. > >> > >> Like 'show route table inetflow.0 extensive' and config. > >> > >> On Sat, 17 Sept 2022 at 05:05, Gustavo Santos via juniper-nsp > >> wrote: > >> > > >> > Hi, > >> > > >> > We have noticed that flowspec is not working or filtering as expected. > >> > Trying a DDoS detection and rule generator tool, and we noticed that the > >> > flowspec rule is installed, > >> > the filter counter is increasing , but no filtering at all. > >> > > >> > For example DDoS traffic from source port UDP port 123 is coming from an > >> > Internet Transit > >> > facing interface AE0. > >> > The destination of this traffic is to a customer Interface ET-0/0/10. > >> > > >> > Even with all information and "show" commands confirming that the traffic > >> > has been filtered, customer and snmp and netflow from the customer facing > >> > interface is showing that the "filtered" traffic is hitting the > >> > destination. > >> > > >> > Is there any caveat or limitation or anyone hit this issue? I tried this > >> > with two MX10003 routers one with 19.R3-xxx and the other one with 20.4R3 > >> > junos branch. > >> > > >> > Regards. > >> > ___ > >> > juniper-nsp mailing list juniper-nsp@puck.nether.net > >> > https://puck.nether.net/mailman/listinfo/juniper-nsp > >> > >> > >> > >> -- > >> ++ytti > > > > -- > ++ytti -- ++ytti ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
Re: [j-nsp] Flowspec not filtering traffic.
Are you exceeding the configured rate for the policer? Did you expect to drop at any rate? The rule sets a non-0 policing rate. On Sat, 17 Sept 2022 at 17:42, Gustavo Santos wrote: > > Hi Saku, > > PS: Real ASN was changed to 65000 on the configuration snippet. > > > > show route table inetflow.0 extensive > > 1x8.2x8.84.34,*,proto=17,port=0/term:7 (1 entry, 1 announced) > TSI: > KRT in dfwd; > Action(s): discard,count > Page 0 idx 0, (group KENTIK_FS type Internal) Type 1 val 0x63b7c098 > (adv_entry) >Advertised metrics: > Flags: NoNexthop > Localpref: 100 > AS path: [65000 I > Communities: traffic-rate:52873:0 > Advertise: 0001 > Path 1x8.2x8.84.34,*,proto=17,port=0 > Vector len 4. Val: 0 > *Flow Preference: 5 > Next hop type: Fictitious, Next hop index: 0 > Address: 0x5214bfc > Next-hop reference count: 22 > Next hop: > State: > Local AS: 52873 > Age: 8w0d 20:30:33 > Validation State: unverified > Task: RT Flow > Announcement bits (2): 0-Flow 1-BGP_RT_Background > AS path: I > Communities: traffic-rate:65000:0 > > show firewall > > Filter: __flowspec_default_inet__ > Counters: > NameBytes Packets > 1x8.2x8.84.34,*,proto=17,port=0 19897391083510189535 > > > BGP Group > > {master}[edit protocols bgp group KENTIK_FS] > type internal; > hold-time 720; > mtu-discovery; > family inet { > unicast; > flow { > no-validate flowspec-import; > } > } > } > > > > Import policy > {master}[edit] > gustavo@MX10K3# edit policy-options policy-statement flowspec-import > > {master}[edit policy-options policy-statement flowspec-import] > gustavo@MX10K3# show > term 1 { > then accept; > } > > IP transit interface > > {master}[edit interfaces ae0 unit 10] > gustavo@MX10K3# show > vlan-id 10; > family inet { > mtu 1500; > filter { > inactive: input ddos; > } > sampling { > input; > } > address x.x.x.x.x/31; > } > > > Em sáb., 17 de set. de 2022 às 03:00, Saku Ytti escreveu: >> >> Can you provide some output. >> >> Like 'show route table inetflow.0 extensive' and config. >> >> On Sat, 17 Sept 2022 at 05:05, Gustavo Santos via juniper-nsp >> wrote: >> > >> > Hi, >> > >> > We have noticed that flowspec is not working or filtering as expected. >> > Trying a DDoS detection and rule generator tool, and we noticed that the >> > flowspec rule is installed, >> > the filter counter is increasing , but no filtering at all. >> > >> > For example DDoS traffic from source port UDP port 123 is coming from an >> > Internet Transit >> > facing interface AE0. >> > The destination of this traffic is to a customer Interface ET-0/0/10. >> > >> > Even with all information and "show" commands confirming that the traffic >> > has been filtered, customer and snmp and netflow from the customer facing >> > interface is showing that the "filtered" traffic is hitting the >> > destination. >> > >> > Is there any caveat or limitation or anyone hit this issue? I tried this >> > with two MX10003 routers one with 19.R3-xxx and the other one with 20.4R3 >> > junos branch. >> > >> > Regards. >> > ___ >> > juniper-nsp mailing list juniper-nsp@puck.nether.net >> > https://puck.nether.net/mailman/listinfo/juniper-nsp >> >> >> >> -- >> ++ytti -- ++ytti ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
Re: [j-nsp] Flowspec not filtering traffic.
Hi Saku, PS: Real ASN was changed to 65000 on the configuration snippet. show route table inetflow.0 extensive 1x8.2x8.84.34,*,proto=17,port=0/term:7 (1 entry, 1 announced) TSI: KRT in dfwd; Action(s): discard,count Page 0 idx 0, (group KENTIK_FS type Internal) Type 1 val 0x63b7c098 (adv_entry) Advertised metrics: Flags: NoNexthop Localpref: 100 AS path: [65000 I Communities: traffic-rate:52873:0 Advertise: 0001 Path 1x8.2x8.84.34,*,proto=17,port=0 Vector len 4. Val: 0 *Flow Preference: 5 Next hop type: Fictitious, Next hop index: 0 Address: 0x5214bfc Next-hop reference count: 22 Next hop: State: Local AS: 52873 Age: 8w0d 20:30:33 Validation State: unverified Task: RT Flow Announcement bits (2): 0-Flow 1-BGP_RT_Background AS path: I Communities: traffic-rate:65000:0 show firewall Filter: __flowspec_default_inet__ Counters: NameBytes Packets 1x8.2x8.84.34,*,proto=17,port=0 19897391083 510189535 BGP Group {master}[edit protocols bgp group KENTIK_FS] type internal; hold-time 720; mtu-discovery; family inet { unicast; flow { no-validate flowspec-import; } } } Import policy {master}[edit] gustavo@MX10K3# edit policy-options policy-statement flowspec-import {master}[edit policy-options policy-statement flowspec-import] gustavo@MX10K3# show term 1 { then accept; } IP transit interface {master}[edit interfaces ae0 unit 10] gustavo@MX10K3# show vlan-id 10; family inet { mtu 1500; filter { inactive: input ddos; } sampling { input; } address x.x.x.x.x/31; } Em sáb., 17 de set. de 2022 às 03:00, Saku Ytti escreveu: > Can you provide some output. > > Like 'show route table inetflow.0 extensive' and config. > > On Sat, 17 Sept 2022 at 05:05, Gustavo Santos via juniper-nsp > wrote: > > > > Hi, > > > > We have noticed that flowspec is not working or filtering as expected. > > Trying a DDoS detection and rule generator tool, and we noticed that the > > flowspec rule is installed, > > the filter counter is increasing , but no filtering at all. > > > > For example DDoS traffic from source port UDP port 123 is coming from an > > Internet Transit > > facing interface AE0. > > The destination of this traffic is to a customer Interface ET-0/0/10. > > > > Even with all information and "show" commands confirming that the traffic > > has been filtered, customer and snmp and netflow from the customer facing > > interface is showing that the "filtered" traffic is hitting the > destination. > > > > Is there any caveat or limitation or anyone hit this issue? I tried this > > with two MX10003 routers one with 19.R3-xxx and the other one with 20.4R3 > > junos branch. > > > > Regards. > > ___ > > juniper-nsp mailing list juniper-nsp@puck.nether.net > > https://puck.nether.net/mailman/listinfo/juniper-nsp > > > > -- > ++ytti > ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
Re: [j-nsp] Flowspec not filtering traffic.
Can you provide some output. Like 'show route table inetflow.0 extensive' and config. On Sat, 17 Sept 2022 at 05:05, Gustavo Santos via juniper-nsp wrote: > > Hi, > > We have noticed that flowspec is not working or filtering as expected. > Trying a DDoS detection and rule generator tool, and we noticed that the > flowspec rule is installed, > the filter counter is increasing , but no filtering at all. > > For example DDoS traffic from source port UDP port 123 is coming from an > Internet Transit > facing interface AE0. > The destination of this traffic is to a customer Interface ET-0/0/10. > > Even with all information and "show" commands confirming that the traffic > has been filtered, customer and snmp and netflow from the customer facing > interface is showing that the "filtered" traffic is hitting the destination. > > Is there any caveat or limitation or anyone hit this issue? I tried this > with two MX10003 routers one with 19.R3-xxx and the other one with 20.4R3 > junos branch. > > Regards. > ___ > juniper-nsp mailing list juniper-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/juniper-nsp -- ++ytti ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
[j-nsp] Flowspec not filtering traffic.
Hi, We have noticed that flowspec is not working or filtering as expected. Trying a DDoS detection and rule generator tool, and we noticed that the flowspec rule is installed, the filter counter is increasing , but no filtering at all. For example DDoS traffic from source port UDP port 123 is coming from an Internet Transit facing interface AE0. The destination of this traffic is to a customer Interface ET-0/0/10. Even with all information and "show" commands confirming that the traffic has been filtered, customer and snmp and netflow from the customer facing interface is showing that the "filtered" traffic is hitting the destination. Is there any caveat or limitation or anyone hit this issue? I tried this with two MX10003 routers one with 19.R3-xxx and the other one with 20.4R3 junos branch. Regards. ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp