Cisco Firewall :: 871 - Default Class Map Is Dropping All Packets
Aug 21, 2012
I have a Cisco 871 router that used to have Access list based security. now I am trying the ZBFW for the first time. I thought I had a pretty good program until I found all my traffic was getting dropped. This is my first stab at ZBFWs and I am a bit confused esp with the default class part.
The router is for my house and thus also has to have priority for gaming. I will add the gaming and voice QOS once I get it working,
Guest VLAN has access to 2 IP's in Data for printing. Cisco871#sh run
Current configuration : 8005 bytes
no service pad
I am having an issue where the ASA is dropping packets on the vlan interfaces. I have it as a dedicated router/firewall for a 100mb connection .
Vlan1 is the internal networkVlan2 is the network to cable modem
Eth 0/1 is connected to a 2960G switch with hard coded 100mb Full Duplex at each end, this is the inside interface. Eth 0/0 is the connection to the cable modem, this is the outside interface, set at auto at both ends.
Im getting on the vlans eg. 51253 packets dropped however network traffic isnt impacted and everything runs fine, as well as 46532 switch ingress policy drops.
ciscoasa# sh int vlan1Interface Vlan1 "inside", is up, line protocol is up Hardware is EtherSVI, BW 100 Mbps, DLY 100 usec MAC address 70ca.9b36.ab80, MTU 1500 IP address 10.x.x.x, subnet mask 255.255.255.0 Traffic Statistics for "inside": 43250588
We have a setup with a MS-TMG - ASA (8.2.4(4) in routing mode) - (internal) Router - FWSM - Router - Exchange with NLB. We have now the problem that IMAPS is not really working through this setup. It works from internal (without ASA and TMG inbetween), but not reliably through the internet. There is a rule on the ASA which permits the ports from the TMG to the Exchange NLB address.We opened a case with Microsoft and they told us that not all tcp-syn packets are received by the Exchange server which were sent by the TMG.Thus I sniffed on the ASA with a packet capture and indeed, a lot of syn packets were on the interface to the TMG, but not anymore on the interface to the internal router.This ASA also filters all other internet<->company traffic, so there's a lot of stuff running.
Maybe it's dropped in the ASP, or is the capture maybe not valid?Here the show asp drop:
ASA01-Internet# sh asp drop Frame drop: Invalid TCP Length (invalid-tcp-hdr-length) 1 Reverse-path verify failed (rpf-violated) 319 Flow is denied by configured rule (acl-drop) 477077 First TCP packet not SYN (tcp-not-syn) 10212 TCP data send after FIN (tcp-data-past-fin) 41 TCP failed 3 way handshake (tcp-3whs-failed) 824 TCP RST/FIN out of order (tcp-rstfin-ooo) 1419 TCP SEQ in SYN/SYNACK invalid (tcp-seq-syn-diff) 6 TCP SYNACK on established conn (tcp-synack-ooo) 1 TCP packet SEQ past window (tcp-seq-past-win) 821 TCP invalid ACK
I am attempting to FTP to a remote site through a IPSEC tunnel.When I am transfering large files the ASA5540 is showing syslog errors stating "connection timeout". What I think is happening is after about 1 hour the firewall is closing the connection control port for the FTP session and neither end is notified so eventually the transfer is stopped.What do I need to modify in the FW to accommodate these larger files?
I have 2 ASA 5510 firewalls at 2 different sites. Both running on version 8.0.4. Users are using an Instant Messaging type of application provided by a local telco here which is able to send and receive SMS using SIP (from the packet capture that I've done).
When users use the IM in site A, they are able to send and receive text messages via the IM from behind the firewall. However, when the users are in site B, users are able to send out text messages but not able to receive them.
I noticed that when I remove "inspect sip" from site-B's global policy map, users from site-B can successfully receive text messages. I have confirmed that it is the firewall that drops the packets as I have captured the inside and outside interfaces of site-B's ASA and I can see the incoming sip "request: MESSAGE" packet on the outside interface but I do not see the packet exiting the inside interface.
I have cross check both firewall configurations, and I do not see anything suspicious commands relating to sip that might cause this issue. Is there any command to troubleshoot why the sip inspection is dropping the sip packets on site-B?
I was looking at a problem where a traffic from certain sites have a restricted bandwidth, an ongoing problem for a year or so, apparently this throughput never exceeds around 25Mbps. My customer describes a situation where the end to end utilisation rises, eventually flat-lining at around 25Mbps. how many extra systems come on line, this traffic never exceeds this rate, and end users complain of poor responses.
During my investigation I found that one of the switches (Cat 6509) in the traffic path has a policer configured on a vlan interface, the policer has 3 sections for different traffic based on DSCP markers, and a default (unconfigured) class-default. Various people have had a poke about with this config over the years, with the result that all the traffic has the CoS and DSCP tags set to 0. All this traffic is hitting the class-default in the policer.The link that this traffic hits the Cat 6509 on is a 100Mbps link.
If I was designing this from scratch I'd probably configure a rate for the class-default.my question is, in the case where no specific configuration has been entered for the class-default, how much bandwidth is allocated to this class?
I currently have the default inspection engine configured in my firewall to inspect http traffic. I noticed that the ASA will drop packets when visting legitimate websites. I've tried googling for a workaround but have been unsucsselful. How can I exclude some websites or IP's from being affected by the inspection engine?
I have ASA 5510 with 8.4 connected to ISG 1000, when traffic is passing the VPN tunnel is working fine, when the traffic stops, ASA will drop the packet but the VPN tunnel on ISG still up .When new traffic started from ISG side, it will drop, as the tunnel is not up on ASA side.
We have a cisco 800 series router between the internal network and the WAN. the problem is we are unable to receive some of our mail due to dropped packets by our router. the conversation between the two servers stops at the point were our server responds with the command 250 2.1.5 email@example.com | 354 Start mail input; end with . i was able to trace the packet, using Packet Export, on the internal interface but not on the external interface. Also i have noticed that the external interface has about 160,000 unknown protocol drops while the internal interface has 0.
Is there anyway to find out way the external interface is dropping the packets.
We have a customer who we sent to Cisco to replace some aging Dell switches. They purchased 5 SG300-52’s for 2 different networks. Their production LAN has 2 “live” switches and 1 spare. The 2nd, a development LAN has 1 switch and 1 spare. Their primary production SG300-52 has GE1-8 VLAN’d off as VLAN2 for public IPs. The untrusted (WAN) interfaces of 2 x ASA-5510’s, 1 x ASA-5505, and 2 x RV082 v2’s are connected to GE2-6. GE1 is the uplink to the co-location center’s Cisco switches. GE7 & 8 are spare ports. Each SG and device port is hard coded for 100/Full.
One of the ASA-5510’s and the ASA-5505 maintain a site-to-site VPN (the development LAN used to be in a different facility hence the VPN). Recently the developers have stated the performance is horrible. I noticed ping traffic loss from PCs on the dev side to servers on the production side in the order of 20-30%. I assumed it was a VPN issue so I opened a ticket with Enterprise TAC (all the ASAs and the SGs have either SmartNet or extended support contracts). TAC determined the problem happened even if you ping from inside the ASA to the untrusted side of the other ASA thus eliminating the VPN as the culprit.
The 2nd ASA-5510 has the AIP module and was not even live until this weekend. Turning it up and giving it a basic config returned the same results. #ping x.x.x.x repeat 100 will drop 20-40 packets. I have no security enabled on the SGs and even tried using the spare SG300-52 this weekend in place of their primary with the same result. I’m to the point of returning one of the Dell switches to production, but this cannot be a good sign. I’m also a bit frustrated that I’ve yet to figure out how to get Cisco Enterprise to speak with Cisco Small Business on this. The customer has over $10k invested in Cisco equipment and Cisco isn’t jumping in to figure this out.
The latest rep wants a packet capture from the SG300’s VLAN2 but there are no PCs there to do this with and the manual doesn’t even talk about doing this. How we can do this as well as get the 2 divisions working together to fix this? BTW, the RV082’s exhibit the SAME exact problem. I can ping from ANY device on VLAN2 to any other device and drop packets. Copying a simple 1MB file over the VPN can take minutes where it should take 1 second. I can reproduce this for 24/7.
It appears we might have an issue with our RV082 (v4.2.1.02) dropping packets during the teardown of many TCP conversations. I have attached two packet captures of what I believe is the same conversation. One is from outside the router (Wireshark using an Ethernet Tap) and the other is from the client inside the router (SLES11SP2 running TCPDump). These are both very small captures 9 packets and 18 packets and I'm hoping it will identify the problem.
It appears that the RV082 is prematurely closing the natted port used to communicate with the host outside the network. The host sends a FIN, ACK packet, to which the client responds with an ACK, However, when the client then sends his FIN,ACK sequence, it never makes it outside the router. The client sends a total of 9 FIN,ACKs trying to contact the outside server, but none of those appear to make it through the router.
Is the router slamming the door prematurely? (I've been fighting with this problem for 3 weeks now!)
We have a Cisco ASA and recently purchased a cisco small business srp527 router. It is connected to our ADSL2 connection and is working fine. I have configured the device with an ipsec tunnel using an ike profile and the tunnel is created successfully with packets traversing the tunnel. However packets are being dropped intermittently, with no cause. The link is currently not being utilised, there is no load on the network however when I ping Google and any address subject to the rules of the tunnel i notice that a single packet is dropped every now and then.
I seem to be having an issue where certain very packets are being dropped/lost by my office router. The reproducible situation is, when I attempt a DNS zone transfer from my linux bind DNS server (A.A.A.A) to any server on my network behind NAT (Y.Y.Y.Y) the first packet (Seq 1) of the response is lost. The client making the query asks for first packet (Seq 1) to be resent, and the DNS server attempts to resend it repeatedly, but those are lost too.
We have a customer who uses about 20 x c2960's switches for access layer and 2 x c3560e for distribution layer. C2960's uses C2960-LANLITEK9-M , Version 12.2(58)SE1. Everything was working fine. Now we got information, that sometimes there are problems with connectivity. Customer tries to reach internet.
SW11#sh int fa0/18 FastEthernet0/18 is up, line protocol is up (connected) Hardware is Fast Ethernet, address is e8ba.806a.4412 (bia e8ba.806a.4412)
I am trying to find a solution using modular QOS when there is congestion in circuit we drop packets with WRED which are marked with a DSCP value of say AF21. I can drop those traffic completely in case of congestion. I was thinking to allocate 100% bandiwth to rest of the traffic.
I bought a DIR-655 a less than a year ago on amazon, and it was working great up until about 4 weeks ago. Ive noticed that it has been dropping alot of packets while I am gaming on my computer. I would run about 95-98 ping usually and now it jitters every 5-10 mins or so from 95-98 to up to 500. It is really troublesome during games and I dont know what to do. Ive tried disabling QoS and still nothing. I run on wireless G and N with auto 20/40 mhz. Standard WPA(personal) and it was running absolutely great until now. I know its the wireless because I have hardwired it into my laptop, both from the router and just the modem itself with no problems whatsoever. I dont know what to do about it.
I have a laptop computer with windows 7 and im having trouble connecting to my wireless internet. It says that im receiving packets but not sending them. I have tried to troubleshoot the problem and it says that the default gateway is not available. I am not sure what is happening with it, it started having problems while at a starbucks, and now the wireless and the LAN is not working on it.
I have a ACE module A2(3.5) installed, I am having a connectivity problem between two servers in my network. I have captured some traffic on different points in my network and from capture it seems like the problem is with this ACE module or somehow it is closing the connection.
I recently installed DHCP snooping on a 3750v2 switch (Version 12.2(55)SE4) and configured the uplink(Po2) as a trusted port. The problem is that clients cannot receive an IP address. When I disable DHCP snooping it is working properly. DHCP snooping is configured correctly but I don't have an idea how to resolve it. [code]I tested the solution on the same kind of hardware switch and firmware and it worked out fine. What is causing the clients not to receive an IP address from the DHCP server?
We have a remote site that is using 3750X switches as layer 2 switches back to our home site. The uplink port is showing dropped packets but the utilization on the link is never about 10%. We have a 100Mb circuit to this site. Our speed tests and iperf tests are not showing any issues that we can see. However the port is still droping packets. It is not dropping at a high rate but they are dropping.
We are testing a new 1Gbps WAN circuit between 2 sites. We have cisco 3750 and 4507 on each end. Every time we run extended ping sweep ranging from 36 to 18024 bytes the packets are being dropped randomly once the size goes above 1500 bytes. Our ISP claims Demark to Demark test are clean and they don't want to acknowledge the problem, they blame our switches. To prove the problem is not on our end we've put different switches at each end, still facing the same issue. Ping success rate is around 98 to 99 percent.
I am trying to use my WRT120n as access device for an IP Centrex service using SIP protocol. My SIP phone is located right behind the router.My problem is sometimes the router is dropping incoming calls because signalling packets are fragmented at IP level. So I cannot receive those calls.Is there a way to enable the router to accept these packets?
I have a request for blocking urls using a class map. I have made this work with HTTP, however it does not work for https. This is a 2851 router with IOS Version 12.4(15)T7. I see i could use the command "match protocol secure-https" however this does not let me specify any specific urls.
Does a new IOS version will support what I'm trying to do? Or if there is another way?
I am carving up an internet Class C for customer. This class C is used by 3 distinct QA, Corporate and Production firewalls. I want to carve up IP space so there is a /26 for each environment. The issue I have is the firewalls may need communication with each other via the public IP space. Currently I don’t have any L3 switches in between the firewalls and the edge internet router. So with subnetting, it would seem I need to push everything through the internet router for the intra-firewall communication.I would rather not push this traffic through the edge router, so I came up with an idea to allocate all firewall outside interface IP’s in the 4th (last remaining) /26. That way, I can allow firewalls to communicate over the primary interface IP’s, which will all be in the same subnet – without going through a routing “engine”/device.
For the actual environment subnets (NAT's on respective firewalls), I create a static route on the edge router pointing to each of the firewall’s primary IP’s for the respective environment routes (the first 3 - /26’s).This is still a beta design, but I have done this before on small scale when ISP gave me 2 subnets for example, assuming I was going to put a router in between the customer firewall and ISP. I would use the “routed subnet” on the ASA interface, and then pull the NAT’s from the other subnet. The ISP would have to add a static route directing the NAT subnet to the “routed subnet” correct IP - which would be the firewall outside interface primary IP.I recently found out that with ASA OS 8.4.3 and up, ASA will not proxy arp for IP’s not in its local interface subnet. This means the ISP/router will have to assign static ARP entries on the edge router. This can get messy after the first few NAT entries. So I am debating the design now. I think this kind of stuff going forward won’t be worthwhile with newer ASA 8.4.3 code.
How to communicate between different ASA’s, while still carving up the Class C into usable smaller subnets? The primary reason for doing this in the first place is to support routing on the edge router. I am thinking it might be time to ask for another Class C to do the routing functions, and keep the firewalls all at Layer 2 in one /24 - Class C?
I'm trying to support a friend. They just switched to TWC Business Class from Megapath. They have a Cisco 5505 ASA and are trying to configure it to work with the new TimeWarner cable modem. But we can't get PCs behind the firewall out to the Internet.
We think it should be a pretty simple config. They have the ASA connected directly to the modem. The modem is running DHCP, and we''ve configured the ASA to get its address via DHCP. We have a Windows server behind the firewall; it can't get out the Internet either. It's set up to be a DHCP server and is giving IP addresses to the PCs on the network.
Laptops connected via wifi to a wireless router attached to the modem are able to connect to the internet, thus we know the modem is up and running fine.
My wireless connection keeps dropping. It tells me the default gateway is not available.I have tried to check and do the things told here first but not working have tried to do the driver update . I have a realtek driver, there is no update available for it.I have a 25 mbit connection i barely get 1 mbit.Extremely slow The laptop is running windows 7 .Also i already did all the TCP/IP stack repair options like winsock reset etc.The antivirus i am running is ESET Nod32 version 4 i think .I have attached a xirrus wifi inspector photo if u want to look at it.[CODE]
I got myself lately Cisco SR520 router with some basic firewall functions built in. This is going to be used for my home broadband, so no need to be really super secure, as it would be for some business. I managed to configure it, however there are few things on the firewall side, which I don't understand.
This router had some default configuration in it's flash, when I bought it. There are class maps.... how it works or how to add/edit rules. Also, do I need to use class maps, or can they be replaced by ACL's to certain extend? How to add/edit class maps rules to allow certain port (eg. 3333). Pease see below part of the default config:
class-map type inspect match-any SDM-Voice-permit match protocol sip class-map type inspect match-any sdm-cls-icmp-access match protocol icmp match protocol tcp [Code]...
I'm trying to configure a zone-based firewall on an SR520 and am confused about the 'not' criterion. The 'zone-design-guide' says (my stress): Class- maps define the traffic that the firewall selects for policy application. Layer 4 class-maps sort the traffic based on these criteria listed here. These criteria are specified using the match.where my intention is to let only LAN hosts with IPs in the range 192.168.1.1 to 192.168.1.7 out through the firewall. There may be an easier way of doing this which I'd be pleased to hear about. But, even if there is, I'd also be interested to know what I'm doing wrong in the above.
I installed Windows 7 a few weeks back with no hitches but over the last week I have been getting regularly kicked off line with above message that the default gateway was not available! Fortunately the Windows troubleshooter fixes it every time but intrigued why it keeps happening.I have reset the adaptor and the router but still no luck!