networking – Ubuntu transmits TTL 0 multicast packets

IP packets with TTL 0 shall not leave host.

But when I start application which multicasts UDP packets with TTL 0, I see packets with TTL 0 leaving host for few seconds, and coming to normal behavior of TTL 0. This most likely happens after reboot and first start of application.

I confirmed packets with TTL 0 leaving host with tcpdump:

05:31:39.048304 IP (tos 0x0, id 14487, offset 0, flags (DF), proto UDP (17), length 1344) > UDP, length 1316
05:31:39.049594 IP (tos 0x0, id 14488, offset 0, flags (DF), proto UDP (17), length 1344) > UDP, length 1316
05:31:39.051601 IP (tos 0x0, id 14489, offset 0, flags (DF), proto UDP (17), length 1344) > UDP, length 1316
05:31:39.053584 IP (tos 0x0, id 14490, offset 0, flags (DF), proto UDP (17), length 1344) > UDP, length 1316

As we can see ttl is not displayed which means TTL 0, as confirmed from tcpdump man page: (search ttl, it clearly indicated: ttl is the time-to-live; it is not reported if it is zero).

There are no any iptables rules running.

uname -a: Linux mydevice 4.15.0-101-generic #102-Ubuntu SMP Mon May 11 10:07:26 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

lsb_release -a:

No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.4 LTS
Release:        18.04
Codename:       bionic

What can be the cause for this behavior, and how can I resolve this?

The spam that transmits postfix config "the host name does not resolve to address: no address associated with the host name"

On a postfix MX MTA configuration, I do two spam checks, which should absolutely not be the case.

the postfix/smtpd process saves these warnings, which should to be a difficult failure in this configuration:

  • hostname * does not resolve to address *: No address associated with hostname
  • Unable to look up MX host * for Helo command *: No address associated with hostname

The relevant mail log is:

postfix/smtpd: warning: hostname does not resolve to address No address associated with hostname
postfix/smtpd: connect from unknown(
postfix/smtpd: warning: Unable to look up MX host for Helo command No address associated with hostname
policyd-spf: prepend Received-SPF: Neutral (mailfrom) identity=mailfrom; client-ip=;;; receiver=
postgrey: action=greylist, reason=new, client_name=unknown, client_address=,, recipient=

It should not even touch blocking lists or additional checks that would block it later.
Here's why:

  • has a PTR record, but this domain does not have an IP A / AAAA record (or MX record).
  • HELO's has an MX record, but this subdomain does not have an IP A / AAAA record.

I can not find any postconf parameters that could turn these warnings into errors, and I wonder if I should write my own check here.
postfix Is save the warnings, he is aware of the problems, so hope I miss something?

The MTA configuration has

smtpd_delay_reject = yes    
smtpd_helo_required = yes
smtpd_helo_restrictions =


smtpd_sender_restrictions =

and I would have thought that one or the other or both should remove that link, but on closer inspection, these checks seem insufficient here:

rejeter_unknown_helo_hostname: Reject the request when the HELO or EHLO host name does not have a DNS A or MX record.

Clearly, the HELO domain has an A and MX record (only the MX can not resolve). So, that seems to be passing.

refuse_unknown_sender_domain: Reject the request when Postfix is ​​not the final destination of the sender's address and the domain MAIL FROM is not 1) DNS MX and no DNS record A, or 2) a malformed MX record such as a record with a null-length MX hostname

MAIL OF ( is clearly falsified, so it does not help at all?

angular 2+ – Angular8 transmits all data through FormGroup

How to improve this code? Is it possible to delete fields comes, html and passes all the necessary data through FormGroup?


import { Component } from '@angular/core';
import { FormGroup, FormBuilder, FormControl } from '@angular/forms';

  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ('./app.component.css')
export class AppComponent {

  myForm: FormGroup;

  fields = (
    { label: "Drill Bit Type", name: "drillBitType", options: ("Masonry", "SDS", "Universal"), type: "mat-input" },
    { label: "Drill Bit SharpAngel", name: "drillBitSharpAngel", options: ("118", "120", "135"), type: "mat-select" },
    { label: "Drill Bit Sharp Direction", name: "drillBitSharpDirection", options: ("Left", "Right"), type: "mat-select" });

  constructor(private formBuilder: FormBuilder) {
    let dictionary: { (key: string): FormControl; } = {};
    this.fields.forEach(element => {
      dictionary( = new FormControl(element.label);
    this.myForm = new FormGroup(dictionary);

  Submit() {
    this.fields.forEach(element => {


{{field.label}} {{option}}

magento2 – Magento 2 transmits phtml template data to js file

I want to call an ajax function on a button click. All other things work well. But I can not read the parameter that is passed to js. How can I do it? Here is my code.

Phtml file

<type of entry = "text" id = "name" class = "name" maxlength = "8" placeholder = "EscapeHtml (__ (ENTER THE NAME))?> "> <type of entry = "button" value = "escapeHtml (__ (CHECK)) ?? "" id = "check-button">

JS file

), function ($, mageTemplate, alert){

           url: config.ajaxurl,
           type: 'POST',
           dataType: 'json',
           data: {name: $('#name').val()},
           complete: function(response) {   
              if (response.responseJSON.success) {
                 jQuery("#successmsg").attr('style','display: block');                 


unit – How to make sure that an audio source transmits 2 specific scenes?

I am working on an audio source for my main menu and I am helping the scenes I want to wear on both scenes but be destroyed on all the other scenes. I encounter many problems, for example if it does not destroy on other scenes or if I come back to the previous scene, it generates 2 audio sources, etc. Here is the script:

public class DestroyAudio : MonoBehaviour
    void Awake()
        SceneManager.sceneLoaded += OnSceneLoaded;

    void OnSceneLoaded(UnityEngine.SceneManagement.Scene scene, UnityEngine.SceneManagement.LoadSceneMode mode)
        if (( == "Help") || ( == "Main Menu"))

angular 2+ – transmits the contents of an observable and future object to an output

selector: "quickfilter app",
templateUrl: & # 39; ./ quickfilter.component.html & # 39;
styleUrls: ['./quickfilter.component.scss']
QuickfilterComponent export class {

@Input () filterConfig;
userInput: string;
tableData $: observable;
@Output () tableData = new EventEmitter();

constructor (private filterService: FilterService) {}

onUserInput (input: string) {
this.userInput = input;

// refresh
this.tableData $ = this.getTableData $ ();

getTableData $ () {
const filterConfig = this.filterConfig;

// create an observable to contact a webservice
// and to transform the return value of a table.
let filterResult $: Observable = this.filterService.getQuickFilter $ (userInput);
return filterResult $ .pipe (map (result)) => TableDataUtil.forInvocationResult (result)));

The component takes an entry filterConfig which contains the configuration for rendering a text field. Once the user has entered the data into the text field, the onUserInput () method is called. This will trigger an update, the getTableData $ () the method prepares an observable which can be used to retrieve the data from the server.

Now, all my questions about this code, go to @Exit. Something is missing here. When headphones are registered in the output (ie TableData emitter event), so this should actually subscribe them to the tableData $.

So, in other words, how can we transfer or link the contents of the tableData $ observable at the TableData exit ? I wonder what would be the advanced solution for that.

And one thing I'm not sure of is how tableData $ is replaced with each refresh. Is not it strange to replace an observable? Would not it make more sense to simply update the contents of the observable and not replace the entire object. (I guess this is very related / relevant to the other question).

magento2 – Magento 2 transmits the data from the html template to the phtml file

Until here I created the folder MyModule / ProductAlert / view / frontend / email / stock.html

{{template config_path = "design / email / header_template"}}

{{var alertGrid | raw}}

{{template config_path = "design / email / footer_template"}}

And I would like to pass my variable E-mail in a .phtml file
MyModule / ProductAlert / view / frontend / templates / email / stock.phtml and call him there –


    getProducts ()):?>

Your email: getData (& # 39;) & # 39;)?>

// Email should be here

Currently he is not returning anything to me. How can I get there? Thank you!

mobile – A Bot telegram that copies and transmits messages from a chat or group?

I do not know if it's the right community, so if I'm wrong, tell me where I should write …

However, I would like to know if there are robots telegrams that automatically copy and transmit messages in a discussion (in a channel or group) and transfer them elsewhere (in a discussion, a channel or a group) .

I am asking you because I would like to create a paid bot that sends notifications, so any user wishing to use the bot has to pay.
However, I would not want in the same chat, group, channel where the "my bot" is, there is another bot that copies "my messages" by transferring them elsewhere.

This way, other users use my service without paying …

entity structure – Transmits information from one datagridview to another datagridview in another form in C #

Hello, I have two forms, both with 1 datagridview each, I would like to click on the line form2 datagridview for the record to be added to the datagridview of form1, could they m & # 39; help?

Note: I use persistence in Entity-framework for the popular datagridview of form2.